#include <bits/stdc++.h>

using namespace std;

int main() {
    double x1, y1, x2, y2;
    cin >> x1 >> y1;
    double sum = 0;
    while (cin >> x1 >> y1 >> x2 >> y2) {
        double dx = x1 - x2;
        double dy = y1 - y2;
        // 欧几里得距离
        sum += sqrt(dx * dx + dy * dy) * 2;
    }
    // 20千米/小时
    int minutes = round(sum / 1000 / 20 * 60);
    int hours = minutes / 60;
    minutes %= 60;
    printf("%d:%02d\n", hours, minutes);
    return 0;
}