#include <iostream>
#include <cmath>
using namespace std;
int main() {
int temp;
cin >> temp >> temp;
double lengthOfRoads = 0;
double firstX, firstY, secondX, secondY;
while (cin >> firstX >> firstY >> secondX >> secondY)
{
lengthOfRoads += sqrt((secondX - firstX)*(secondX - firstX)+(secondY - firstY)*(secondY - firstY));
}
int minutes = round(3 * lengthOfRoads / 500);
cout<< minutes / 60 << ":" << minutes % 60;
return 0;
}
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