// UVA #579
// Difficulty: Easy
// Time:
// Space:
// Stl: 


#include <iostream>
#include <algorithm>
using namespace std;

int main() {

    while (1) {

        double h, m, ans;

        cin >> h; cin.get();
        cin >> m;

        if(!h && !m)break;

        ans = max(6 * m, 30 * (h + m / 60))-min(6 * m, 30 * (h + m / 60));

        if (ans > 180)ans = 360 - ans;

        printf("%.3f\n", ans);
    }

    system("PAUSE");
}