#include <iostream>

#include <cmath>

using namespace std;

​

int main() {

  cout << log10(120.0f) << "\n";

  cout << log10(10.0f) << "\n";

  cout << log10(3.1623) << "\n";

  cout << log10(1.0) << "\n";

  cout << log10(0.0f) << "\n";

  cout << log10(-1.0f) << "\n";

  return 0;

}

​