int reverse(int x)
{
	long long int r = 0;
	while (x)
	{
		r = r * 10 + (x % 10);
		x /= 10;
	}
	if (r > 2147483647)
		return 0;
	if (r < -2147483648)
		return 0;
	return (int)r;
}