#include <iostream>
#include <cmath>
using namespace std;
 
const double pi = 3.14159265358979;
 
int main()
{
    cout <<sin(pi) <<endl
         <<sin(2*pi) <<endl
         <<sin(pi/2) <<endl
         <<sin(pi*3/2) <<endl;
    return 0;
}

3.23109e-15
-6.46217e-15
1
-1