init

fluid/neural_machine_translation/transformer/config.py

 class TrainTaskConfig(object):
+    use_gpu = False
     # the epoch number to train.
     pass_num = 2
 

fluid/neural_machine_translation/transformer/nmt_fluid.py

+import os
+import numpy as np
+import time
+import argparse
+
+import paddle
+import paddle.fluid as fluid
+import paddle.fluid.core as core
+
+from model import transformer, position_encoding_init
+from optim import LearningRateScheduler
+from config import TrainTaskConfig, ModelHyperParams, pos_enc_param_names, \
+        encoder_input_data_names, decoder_input_data_names, label_data_names
+
+def str2bool(v):
+    if v.lower() in ('yes', 'true', 't', 'y', '1'):
+        return True
+    elif v.lower() in ('no', 'false', 'f', 'n', '0'):
+        return False
+    else:
+        raise argparse.ArgumentTypeError('Boolean value expected.')
+
+parser = argparse.ArgumentParser(description=__doc__)
+parser.add_argument(
+    '--batch_size', type=int, default=TrainTaskConfig.batch_size, help="Batch size for training.")
+
+parser.add_argument(
+    '--learning_rate',
+    type=float,
+    default=TrainTaskConfig.learning_rate,
+    help="Learning rate for training.")
+
+parser.add_argument('--num_passes', type=int, default=50, help="No. of passes.")
+
+parser.add_argument(
+    '--device',
+    type=str,
+    default='CPU',
+    choices=['CPU', 'GPU'],
+    help="The device type.")
+
+parser.add_argument('--device_id', type=int, default=0, help="The device id.")
+
+parser.add_argument(
+    '--local',
+    type=str2bool,
+    default=True,
+    help='Whether to run as local mode.')
+
+parser.add_argument(
+    "--ps_hosts",
+    type=str,
+    default="",
+    help="Comma-separated list of hostname:port pairs")
+
+parser.add_argument(
+    "--trainer_hosts",
+    type=str,
+    default="",
+    help="Comma-separated list of hostname:port pairs")
+
+parser.add_argument(
+    "--pass_num",
+    type=int,
+    default=TrainTaskConfig.pass_num,
+    help="pass num of train")
+
+# Flags for defining the tf.train.Server
+parser.add_argument(
+    "--task_index", type=int, default=0, help="Index of task within the job")
+args = parser.parse_args()
+
+def pad_batch_data(insts,
+                   pad_idx,
+                   n_head,
+                   is_target=False,
+                   return_pos=True,
+                   return_attn_bias=True,
+                   return_max_len=True):
+    """
+    Pad the instances to the max sequence length in batch, and generate the
+    corresponding position data and attention bias.
+    """
+    return_list = []
+    max_len = max(len(inst) for inst in insts)
+    inst_data = np.array(
+        [inst + [pad_idx] * (max_len - len(inst)) for inst in insts])
+    return_list += [inst_data.astype("int64").reshape([-1, 1])]
+    if return_pos:
+        inst_pos = np.array([[
+            pos_i + 1 if w_i != pad_idx else 0 for pos_i, w_i in enumerate(inst)
+        ] for inst in inst_data])
+
+        return_list += [inst_pos.astype("int64").reshape([-1, 1])]
+    if return_attn_bias:
+        if is_target:
+            # This is used to avoid attention on paddings and subsequent
+            # words.
+            slf_attn_bias_data = np.ones((inst_data.shape[0], max_len, max_len))
+            slf_attn_bias_data = np.triu(slf_attn_bias_data, 1).reshape(
+                [-1, 1, max_len, max_len])
+            slf_attn_bias_data = np.tile(slf_attn_bias_data,
+                                         [1, n_head, 1, 1]) * [-1e9]
+        else:
+            # This is used to avoid attention on paddings.
+            slf_attn_bias_data = np.array([[0] * len(inst) + [-1e9] *
+                                           (max_len - len(inst))
+                                           for inst in insts])
+            slf_attn_bias_data = np.tile(
+                slf_attn_bias_data.reshape([-1, 1, 1, max_len]),
+                [1, n_head, max_len, 1])
+        return_list += [slf_attn_bias_data.astype("float32")]
+    if return_max_len:
+        return_list += [max_len]
+    return return_list if len(return_list) > 1 else return_list[0]
+
+
+def prepare_batch_input(insts, input_data_names, src_pad_idx, trg_pad_idx,
+                        max_length, n_head):
+    """
+    Put all padded data needed by training into a dict.
+    """
+    src_word, src_pos, src_slf_attn_bias, src_max_len = pad_batch_data(
+        [inst[0] for inst in insts], src_pad_idx, n_head, is_target=False)
+    trg_word, trg_pos, trg_slf_attn_bias, trg_max_len = pad_batch_data(
+        [inst[1] for inst in insts], trg_pad_idx, n_head, is_target=True)
+    trg_src_attn_bias = np.tile(src_slf_attn_bias[:, :, ::src_max_len, :],
+                                [1, 1, trg_max_len, 1]).astype("float32")
+    lbl_word = pad_batch_data([inst[2] for inst in insts], trg_pad_idx, n_head,
+                              False, False, False, False)
+    lbl_weight = (lbl_word != trg_pad_idx).astype("float32").reshape([-1, 1])
+    input_dict = dict(
+        zip(input_data_names, [
+            src_word, src_pos, src_slf_attn_bias, trg_word, trg_pos,
+            trg_slf_attn_bias, trg_src_attn_bias, lbl_word, lbl_weight
+        ]))
+    return input_dict
+
+
+def main():
+    place = core.CPUPlace() if args.device == 'CPU' else core.CUDAPlace(
+        args.device_id)
+    exe = fluid.Executor(place)
+
+    cost, predict = transformer(
+        ModelHyperParams.src_vocab_size + 1,
+        ModelHyperParams.trg_vocab_size + 1, ModelHyperParams.max_length + 1,
+        ModelHyperParams.n_layer, ModelHyperParams.n_head,
+        ModelHyperParams.d_key, ModelHyperParams.d_value,
+        ModelHyperParams.d_model, ModelHyperParams.d_inner_hid,
+        ModelHyperParams.dropout, ModelHyperParams.src_pad_idx,
+        ModelHyperParams.trg_pad_idx, ModelHyperParams.pos_pad_idx)
+
+    lr_scheduler = LearningRateScheduler(ModelHyperParams.d_model,
+                                         TrainTaskConfig.warmup_steps, place,
+                                         TrainTaskConfig.learning_rate)
+    optimizer = fluid.optimizer.Adam(
+        learning_rate=lr_scheduler.learning_rate,
+        beta1=TrainTaskConfig.beta1,
+        beta2=TrainTaskConfig.beta2,
+        epsilon=TrainTaskConfig.eps)
+
+    #optimizer.minimize(cost)
+    optimize_ops, params_grads = optimizer.minimize(cost)
+
+    inference_program = fluid.default_main_program().clone()
+    with fluid.program_guard(inference_program):
+        inference_program = fluid.io.get_inference_program([cost])
+
+    def test(exe):
+        test_costs = []
+        #for batch_id, data in enumerate(val_data()):
+        for batch_id, data in enumerate(test_reader()):
+            if len(data) != args.batch_size:
+                continue
+
+            data_input = prepare_batch_input(
+                data, encoder_input_data_names + decoder_input_data_names[:-1] +
+                label_data_names, ModelHyperParams.src_pad_idx,
+                ModelHyperParams.trg_pad_idx, ModelHyperParams.max_length,
+                ModelHyperParams.n_head)
+
+            test_cost = exe.run(test_program,
+                                feed=data_input,
+                                fetch_list=[cost])[0]
+
+            test_costs.append(test_cost)
+        return np.mean(test_costs)
+
+    def train_loop(exe, trainer_prog):
+        ts = time.time()
+        for pass_id in xrange(args.pass_num):
+            for batch_id, data in enumerate(train_reader()):
+                # The current program desc is coupled with batch_size, thus all
+                # mini-batches must have the same number of instances currently.
+                if len(data) != args.batch_size:
+                    continue
+
+                start_time = time.time()
+                data_input = prepare_batch_input(
+                    data, encoder_input_data_names + decoder_input_data_names[:-1] +
+                    label_data_names, ModelHyperParams.src_pad_idx,
+                    ModelHyperParams.trg_pad_idx, ModelHyperParams.max_length,
+                    ModelHyperParams.n_head)
+
+                lr_scheduler.update_learning_rate(data_input)
+
+                outs = exe.run(fluid.framework.default_main_program(),
+                               feed=data_input,
+                               fetch_list=[cost],
+                               use_program_cache=True)
+
+                cost_val = np.array(outs[0])
+                #print("pass_id = " + str(pass_id) + " batch = " + str(batch_id) +
+                #      " cost = " + str(cost_val) + "Speed = %.2f img/s")
+                print("pass_id = %d batch = %d  cost = %f speed = %.2f sample/s" %
+                      (pass_id, batch_id, cost_val, len(data) / (time.time() - start_time)))
+
+            # Validate and save the model for inference.
+            val_cost = test(exe)
+            #pass_elapsed = time.time() - start_time
+            #print("pass_id = " + str(pass_id) + " val_cost = " + str(val_cost))
+            print("pass_id = %d batch = %d  cost = %f speed = %.2f sample/s" %
+                  (pass_id, batch_id, cost_val, len(data) / (time.time() - ts)))
+
+    if args.local:
+        # Initialize the parameters.
+        exe.run(fluid.framework.default_startup_program())
+        for pos_enc_param_name in pos_enc_param_names:
+            pos_enc_param = fluid.global_scope().find_var(
+                pos_enc_param_name).get_tensor()
+            pos_enc_param.set(
+                position_encoding_init(ModelHyperParams.max_length + 1,
+                                       ModelHyperParams.d_model), place)
+
+        train_reader = paddle.batch(
+            paddle.reader.shuffle(
+                paddle.dataset.wmt16.train(ModelHyperParams.src_vocab_size,
+                                           ModelHyperParams.trg_vocab_size),
+                buf_size=100000),
+            batch_size=args.batch_size)
+
+        test_reader = paddle.batch(
+            paddle.dataset.wmt16.validation(ModelHyperParams.src_vocab_size,
+                                            ModelHyperParams.trg_vocab_size),
+            batch_size=args.batch_size)
+
+        train_loop(exe, fluid.default_main_program())
+    else:
+        trainers = int(os.getenv("TRAINERS"))  # total trainer count
+        print("trainers total: ", trainers)
+
+        training_role = os.getenv(
+            "TRAINING_ROLE",
+            "TRAINER")  # get the training role: trainer/pserver
+
+        t = fluid.DistributeTranspiler()
+        t.transpile(
+            optimize_ops,
+            params_grads,
+            trainer_id=args.task_index,
+            pservers=args.ps_hosts,
+            trainers=trainers)
+
+        if training_role == "PSERVER":
+            current_endpoint = os.getenv("POD_IP") + ":" + os.getenv(
+                "PADDLE_INIT_PORT")
+            if not current_endpoint:
+                print("need env SERVER_ENDPOINT")
+                exit(1)
+            pserver_prog = t.get_pserver_program(current_endpoint)
+            pserver_startup = t.get_startup_program(current_endpoint,
+                                                    pserver_prog)
+            exe.run(pserver_startup)
+            exe.run(pserver_prog)
+        elif training_role == "TRAINER":
+            # Parameter initialization
+            exe.run(fluid.default_startup_program())
+
+            train_reader = paddle.batch(
+                paddle.reader.shuffle(
+                    paddle.dataset.wmt16.train(ModelHyperParams.src_vocab_size,
+                                               ModelHyperParams.trg_vocab_size),
+                    buf_size=100000),
+                batch_size=args.batch_size)
+
+            test_reader = paddle.batch(
+                paddle.dataset.wmt16.validation(ModelHyperParams.src_vocab_size,
+                                                ModelHyperParams.trg_vocab_size),
+                batch_size=args.batch_size)
+
+            trainer_prog = t.get_trainer_program()
+            # feeder = fluid.DataFeeder(feed_list=[images, label], place=place)
+            # TODO(typhoonzero): change trainer startup program to fetch parameters from pserver
+            exe.run(fluid.default_startup_program())
+            train_loop(exe, trainer_prog)
+        else:
+            print("environment var TRAINER_ROLE should be TRAINER os PSERVER")
+
+def print_arguments():
+    print('-----------  Configuration Arguments -----------')
+    for arg, value in sorted(vars(args).iteritems()):
+        print('%s: %s' % (arg, value))
+    print('------------------------------------------------')
+
+if __name__ == "__main__":
+    main()

fluid/neural_machine_translation/transformer/train.py

 import os
 import numpy as np
 
-import paddle.v2 as paddle
+import paddle
 import paddle.fluid as fluid
 
 from model import transformer, position_encoding_init
@@ -9,65 +9,6 @@ from optim import LearningRateScheduler
 from config import TrainTaskConfig, ModelHyperParams, pos_enc_param_names, \
         encoder_input_data_names, decoder_input_data_names, label_data_names
 
-def str2bool(v):
-    if v.lower() in ('yes', 'true', 't', 'y', '1'):
-        return True
-    elif v.lower() in ('no', 'false', 'f', 'n', '0'):
-        return False
-    else:
-        raise argparse.ArgumentTypeError('Boolean value expected.')
-
-parser = argparse.ArgumentParser(description=__doc__)
-parser.add_argument(
-    '--batch_size', type=int, default=TrainTaskConfig.batch_size, help="Batch size for training.")
-
-parser.add_argument(
-    '--learning_rate',
-    type=float,
-    default=TrainTaskConfig.learning_rate,
-    help="Learning rate for training.")
-
-parser.add_argument('--num_passes', type=int, default=50, help="No. of passes.")
-
-parser.add_argument(
-    '--device',
-    type=str,
-    default='CPU',
-    choices=['CPU', 'GPU'],
-    help="The device type.")
-
-parser.add_argument('--device_id', type=int, default=0, help="The device id.")
-
-parser.add_argument(
-    '--local',
-    type=str2bool,
-    default=True,
-    help='Whether to run as local mode.')
-
-parser.add_argument(
-    "--ps_hosts",
-    type=str,
-    default="",
-    help="Comma-separated list of hostname:port pairs")
-
-parser.add_argument(
-    "--trainer_hosts",
-    type=str,
-    default="",
-    help="Comma-separated list of hostname:port pairs")
-
-parser.add_argument(
-    "--pass_num",
-    type=int,
-    default=TrainTaskConfig.pass_num,
-    help="Comma-separated list of hostname:port pairs")
-
-
-# Flags for defining the tf.train.Server
-parser.add_argument(
-    "--task_index", type=int, default=0, help="Index of task within the job")
-args = parser.parse_args()
-
 
 def pad_batch_data(insts,
                    pad_idx,
@@ -125,20 +66,35 @@ def prepare_batch_input(insts, input_data_names, src_pad_idx, trg_pad_idx,
         [inst[1] for inst in insts], trg_pad_idx, n_head, is_target=True)
     trg_src_attn_bias = np.tile(src_slf_attn_bias[:, :, ::src_max_len, :],
                                 [1, 1, trg_max_len, 1]).astype("float32")
+    src_slf_attn_pre_softmax_shape = np.array(
+        [-1, src_slf_attn_bias.shape[-1]], dtype="int32")
+    src_slf_attn_post_softmax_shape = np.array(
+        src_slf_attn_bias.shape, dtype="int32")
+    trg_slf_attn_pre_softmax_shape = np.array(
+        [-1, trg_slf_attn_bias.shape[-1]], dtype="int32")
+    trg_slf_attn_post_softmax_shape = np.array(
+        trg_slf_attn_bias.shape, dtype="int32")
+    trg_src_attn_pre_softmax_shape = np.array(
+        [-1, trg_src_attn_bias.shape[-1]], dtype="int32")
+    trg_src_attn_post_softmax_shape = np.array(
+        trg_src_attn_bias.shape, dtype="int32")
     lbl_word = pad_batch_data([inst[2] for inst in insts], trg_pad_idx, n_head,
                               False, False, False, False)
     lbl_weight = (lbl_word != trg_pad_idx).astype("float32").reshape([-1, 1])
     input_dict = dict(
         zip(input_data_names, [
-            src_word, src_pos, src_slf_attn_bias, trg_word, trg_pos,
-            trg_slf_attn_bias, trg_src_attn_bias, lbl_word, lbl_weight
+            src_word, src_pos, src_slf_attn_bias,
+            src_slf_attn_pre_softmax_shape, src_slf_attn_post_softmax_shape,
+            trg_word, trg_pos, trg_slf_attn_bias, trg_src_attn_bias,
+            trg_slf_attn_pre_softmax_shape, trg_slf_attn_post_softmax_shape,
+            trg_src_attn_pre_softmax_shape, trg_src_attn_post_softmax_shape,
+            lbl_word, lbl_weight
         ]))
     return input_dict
 
 
 def main():
-    place = core.CPUPlace() if args.device == 'CPU' else core.CUDAPlace(
-        args.device_id)
+    place = fluid.CUDAPlace(0) if TrainTaskConfig.use_gpu else fluid.CPUPlace()
     exe = fluid.Executor(place)
 
     cost, predict = transformer(
@@ -160,138 +116,75 @@ def main():
         epsilon=TrainTaskConfig.eps)
     optimizer.minimize(cost)
 
-    inference_program = fluid.default_main_program().clone()
+    train_data = paddle.batch(
+        paddle.reader.shuffle(
+            paddle.dataset.wmt16.train(ModelHyperParams.src_vocab_size,
+                                       ModelHyperParams.trg_vocab_size),
+            buf_size=100000),
+        batch_size=TrainTaskConfig.batch_size)
+
+    # Program to do validation.
+    test_program = fluid.default_main_program().clone()
     with fluid.program_guard(test_program):
-        inference_program = fluid.io.get_inference_program([cost])
+        test_program = fluid.io.get_inference_program([cost])
+    val_data = paddle.batch(
+        paddle.dataset.wmt16.validation(ModelHyperParams.src_vocab_size,
+                                        ModelHyperParams.trg_vocab_size),
+        batch_size=TrainTaskConfig.batch_size)
 
     def test(exe):
         test_costs = []
-        #for batch_id, data in enumerate(val_data()):
-        for batch_id, data in enumerate(test_reader()):
-            if len(data) != args.batch_size:
+        for batch_id, data in enumerate(val_data()):
+            if len(data) != TrainTaskConfig.batch_size:
                 continue
-
             data_input = prepare_batch_input(
                 data, encoder_input_data_names + decoder_input_data_names[:-1] +
                 label_data_names, ModelHyperParams.src_pad_idx,
                 ModelHyperParams.trg_pad_idx, ModelHyperParams.max_length,
                 ModelHyperParams.n_head)
-
             test_cost = exe.run(test_program,
                                 feed=data_input,
                                 fetch_list=[cost])[0]
-
             test_costs.append(test_cost)
         return np.mean(test_costs)
 
-    def train_loop(exe, trainer_prog):
-        for pass_id in xrange(args.pass_num):
-            for batch_id, data in enumerate(train_reader()):
-                # The current program desc is coupled with batch_size, thus all
-                # mini-batches must have the same number of instances currently.
-                if len(data) != args.batch_size:
-                    continue
-
-                data_input = prepare_batch_input(
-                    data, encoder_input_data_names + decoder_input_data_names[:-1] +
-                    label_data_names, ModelHyperParams.src_pad_idx,
-                    ModelHyperParams.trg_pad_idx, ModelHyperParams.max_length,
-                    ModelHyperParams.n_head)
-
-                lr_scheduler.update_learning_rate(data_input)
-
-                outs = exe.run(fluid.framework.default_main_program(),
-                               feed=data_input,
-                               fetch_list=[cost],
-                               use_program_cache=True)
-
-                cost_val = np.array(outs[0])
-                print("pass_id = " + str(pass_id) + " batch = " + str(batch_id) +
-                      " cost = " + str(cost_val))
-
-            # Validate and save the model for inference.
-            val_cost = test(exe)
-            print("pass_id = " + str(pass_id) + " val_cost = " + str(val_cost))
-
-    if args.local:
-        # Initialize the parameters.
-        exe.run(fluid.framework.default_startup_program())
-        for pos_enc_param_name in pos_enc_param_names:
-            pos_enc_param = fluid.global_scope().find_var(
-                pos_enc_param_name).get_tensor()
-            pos_enc_param.set(
-                position_encoding_init(ModelHyperParams.max_length + 1,
-                                       ModelHyperParams.d_model), place)
-
-        train_reader = paddle.batch(
-            paddle.reader.shuffle(
-                paddle.dataset.wmt16.train(ModelHyperParams.src_vocab_size,
-                                           ModelHyperParams.trg_vocab_size),
-                buf_size=100000),
-            batch_size=args.batch_size)
-
-        test_reader = paddle.batch(
-            paddle.dataset.wmt16.validation(ModelHyperParams.src_vocab_size,
-                                            ModelHyperParams.trg_vocab_size),
-            batch_size=args.batch_size)
-
-         train_loop(exe, fluid.default_main_program())
-    else:
-        trainers = int(os.getenv("TRAINERS"))  # total trainer count
-        print("trainers total: ", trainers)
-
-        training_role = os.getenv(
-            "TRAINING_ROLE",
-            "TRAINER")  # get the training role: trainer/pserver
-
-        t = fluid.DistributeTranspiler()
-        t.transpile(
-            optimize_ops,
-            params_grads,
-            trainer_id=args.task_index,
-            pservers=args.ps_hosts,
-            trainers=trainers)
-
-        if training_role == "PSERVER":
-            current_endpoint = os.getenv("POD_IP") + ":" + os.getenv(
-                "PADDLE_INIT_PORT")
-            if not current_endpoint:
-                print("need env SERVER_ENDPOINT")
-                exit(1)
-            pserver_prog = t.get_pserver_program(current_endpoint)
-            pserver_startup = t.get_startup_program(current_endpoint,
-                                                    pserver_prog)
-            exe.run(pserver_startup)
-            exe.run(pserver_prog)
-        elif training_role == "TRAINER":
-            # Parameter initialization
-            exe.run(fluid.default_startup_program())
-
-            train_reader = paddle.batch(
-                paddle.reader.shuffle(
-                    paddle.dataset.wmt16.train(ModelHyperParams.src_vocab_size,
-                                               ModelHyperParams.trg_vocab_size),
-                    buf_size=100000),
-                batch_size=args.batch_size)
-
-            test_reader = paddle.batch(
-                paddle.dataset.wmt16.validation(ModelHyperParams.src_vocab_size,
-                                                ModelHyperParams.trg_vocab_size),
-                batch_size=args.batch_size)
-
-            trainer_prog = t.get_trainer_program()
-            # feeder = fluid.DataFeeder(feed_list=[images, label], place=place)
-            # TODO(typhoonzero): change trainer startup program to fetch parameters from pserver
-            exe.run(fluid.default_startup_program())
-            train_loop(exe, trainer_prog)
-        else:
-            print("environment var TRAINER_ROLE should be TRAINER os PSERVER")
+    # Initialize the parameters.
+    exe.run(fluid.framework.default_startup_program())
+    for pos_enc_param_name in pos_enc_param_names:
+        pos_enc_param = fluid.global_scope().find_var(
+            pos_enc_param_name).get_tensor()
+        pos_enc_param.set(
+            position_encoding_init(ModelHyperParams.max_length + 1,
+                                   ModelHyperParams.d_model), place)
+
+    for pass_id in xrange(TrainTaskConfig.pass_num):
+        for batch_id, data in enumerate(train_data()):
+            # The current program desc is coupled with batch_size, thus all
+            # mini-batches must have the same number of instances currently.
+            if len(data) != TrainTaskConfig.batch_size:
+                continue
+            data_input = prepare_batch_input(
+                data, encoder_input_data_names + decoder_input_data_names[:-1] +
+                label_data_names, ModelHyperParams.src_pad_idx,
+                ModelHyperParams.trg_pad_idx, ModelHyperParams.max_length,
+                ModelHyperParams.n_head)
+            lr_scheduler.update_learning_rate(data_input)
+            outs = exe.run(fluid.framework.default_main_program(),
+                           feed=data_input,
+                           fetch_list=[cost],
+                           use_program_cache=True)
+            cost_val = np.array(outs[0])
+            print("pass_id = " + str(pass_id) + " batch = " + str(batch_id) +
+                  " cost = " + str(cost_val))
+        # Validate and save the model for inference.
+        val_cost = test(exe)
+        print("pass_id = " + str(pass_id) + " val_cost = " + str(val_cost))
+        fluid.io.save_inference_model(
+            os.path.join(TrainTaskConfig.model_dir,
+                         "pass_" + str(pass_id) + ".infer.model"),
+            encoder_input_data_names + decoder_input_data_names[:-1],
+            [predict], exe)
 
-def print_arguments():
-    print('-----------  Configuration Arguments -----------')
-    for arg, value in sorted(vars(args).iteritems()):
-        print('%s: %s' % (arg, value))
-    print('------------------------------------------------')
 
 if __name__ == "__main__":
     main()