#include<bits/stdc++.h>
using namespace std;
int main(){
    int v,ans=10,shi,fen,rs,rf;
    double s,num;
    cin>>s>>v;
    num=ceil(s/v);
    ans+=num;
    shi=ceil(ans/60.0);
    fen=ans%60;
    if(shi<=8) rs=8-shi;
    else rs=12-(shi-8);
    if(fen<=60) rf=60-fen;
    else{
        rf=60-(fen-60);
        rs--;
    }
    if(rs<10&&rf<10) printf("0%d:0%d",rs,rf);
    if(rs<10&&rf>10) printf("0%d:%d",rs,rf);
    if(rs>10&&rf<10) printf("%d:0%d",rs,rf);
    if(rs>10&&rf>10) printf("%d:%d",rs,rf);
    return 0;
}