Contest1337/h.c

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

int main()
{
    int x, y, x1, y1;
    double PI = 4.0 * atan(1.0);
    while(~scanf("%d%d%d%d", &x, &y, &x1, &y1))
    {
        x1 -= x,y1 -= y;
        double R = asin(y1 / sqrt((x1 * x1) + (y1 * y1)));
        if (x1 < 0) R = -R - PI;
        double c = R * 360 / 2 / PI;
        printf("%d\n", (110 - (int) c) % 360 / 40 + 1);
    }
    return 0;
}