#include <stdio.h>
#include <stdlib.h>
#include <math.h>
int main()
{
    long long start, endd;
    long long x1, y1, x2, y2;
    double dis = 0;
    scanf("%d%d",&start,&endd);
    while(scanf("%lld%lld%lld%lld",&x1,&y1,&x2,&y2) != EOF){
        dis += sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1));
    }
    double ans = dis * 2 / 1000 / 20;
    long long h = (long long)ans;
    long long m = (long long)((ans - h) * 60 + 0.5);
    printf("%lld:%02lld",h,m);
    return 0;
}
/**************************************************************
	Problem: 2056
	User: admin
	Language: C
	Result: Accepted
	Time:64 ms
	Memory:1144 kb
****************************************************************/