#include <cmath>
#include <cassert>
#include <iostream>
using namespace std;

double f(double angle) {
  double rtn = fmod(angle, 2*M_PI);
  assert(rtn >= -2*M_PI && rtn <= 2*M_PI);
  cout << angle << " -> " << rtn << " = " << rtn/M_PI << "*PI" << endl;
  return rtn;
}

int main() {
  f(0.387629);
  f(3.61709);
  f(1.82318);
  return 0;
}