#include<iostream>
using namespace std;
int main(){
    double s,v,needtime,needhour,needminute,needsecond;
    cin>>s>>v;
    needtime=s/v;
    needhour=int(needtime)/60.0;
    needminute=int(needtime)%60;
    if((needtime-needminute)>0)needminute+=1;
    cout<<"0"<<int(8-needhour)<<":"<<50-needminute<<endl;
    return 0;
    
    
    
}