#include <iostream>
#include <cmath>

int main() {
    // 计算一个数的以10为底的对数
    double number = 100.0;
    double logBase10 = log10(number);

    // 输出结果
    std::cout << "Log base 10 of " << number << " is: " << logBase10 << std::endl;

    return 0;
}