#define _USE_MATH_DEFINES
#include <math.h>
#include <stdio.h>

int main()
{
    double x = 0;
    double y = 0;
    printf("enter x: ");
    scanf_s("%f", &x);
    y = sin(M_PI/x);
    printf("Your result: %.f\n", y);
    return 0;
}