#include <stdio.h>
#include <math.h>
const float PI = 3.1415926535;

double sinx(double x)
{
    double Xn = x;
    double sum = 0.0;
    int i = 1;
    do
    {
        sum += Xn;
        Xn *= -1.0 * x * x / ((2 * i) * (2 * i + 1));
        i++;
    }
    while (fabs(Xn) > 0.0000001);
    return sum;
}

int main()
{
    double x;
    scanf("%lf",&x);
    x *= PI/180.0;
    printf("sinx =%lf\tlibSin =%f",sin(x),sinx(x));
    //~ printf("%.3f",sinx(x));
    return 0;
}