#include<bits/stdc++.h>
using namespace std;
int s,v,fen,shi,hua,sj;
int main(){
	cin>>s>>v;
	if(s%v==0){hua=s/v;}
	else{hua=(s/v)+1;}
	sj=1910-(hua);
	fen=sj%60;
	shi=(sj/60);
	if(shi>24)shi=shi-24;
	if(shi<10){
		if(fen<10){
			cout<<'0'<<shi<<":"<<'0'<<fen;
		}else{cout<<'0'<<shi<<":"<<fen;}
	}else{
		if(fen<10){
			cout<<shi<<":"<<'0'<<fen;
		}else{cout<<shi<<":"<<fen;}
	}
}