#include <iostream>
#include <cmath>

using namespace std;

int main()
{
    freopen("DATA1.txt", "r", stdin);
    freopen("OUT1.txt", "w", stdout);
    int x, y, x1, y1;
    for (int tt = 0; tt < 5; tt++)
    {
        cin >> x >> y >> x1 >> y1;
        double ang = double(atan2(y, x) - atan2(y1, x1)) *  (double)180/3.1415926535;
        cout.setf(ios_base::fixed, ios_base::floatfield);
        cout.precision(1);
        if (ang < 0) ang = 360 + ang;
        ang = round(ang*10)/10;
        cout << ang << endl;
    }
    return 0;
}