#include<bits/stdc++.h>
using namespace std;
int main(){
    int s,v,ss,sh,f;
    cin>>s>>v;
    ss=ceil(s/v)/60;
    sh=7-ss;
    if (sh<=-1){ sh+=24;}
       
    printf("%2d:",sh);
    f=(50-ceil(s/v));
    cout<<f%60-1;
}