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

int main() {
    int t, s, d;
    cin >> t >> s >> d;
    double time = static_cast<double>(d) / s + (24 - (d / s + t)) % 24;
    cout << fixed << setprecision(15) << time << endl;
    return 0;
}