#include<bits/stdc++.h>
using namespace std;
int main(){
	int s,v,m=0,h=0;
	cin>>s>>v;
	if(s%v){
		m=s/v+1;
	}else{
		m=s/v;
	}
	while(1){
		if(m>=60){
			m-=60;
			h++;
		}else{
			break;
		}
	}
	if(h>=8){
		if(m>50){
			h++;
			m-=50;
			cout<<24+7-h<<":"<<50-m;
		}else{
			cout<<24+7-h<<":"<<50-m;
		}			
	}
	if(m>50){
		h++;
		m-=50;
		cout<<0<<7-h<<":"<<50-m;
	}else{
		cout<<0<<7-h<<":"<<50-m;
	}
	return 0;
}

rt %%%