#include<bits/stdc++.h>
using namespace std;
int main(){
	long long s,v,a,h,m;
	cin>>s>>v;
	if(s%v==0){
		a=s/v+10;
	}else{
		a=s/v+10+1;
	}
	h=a/60;
	m=a%60;
	h=8-h;
	m=60-m;
	if(a<10){
		h+=24;
	}
	if(h<10){
		cout<<0<<h;
	}else{
		cout<<h;
	}
	if(m==60){
		cout<<":"<<00;
	}else if(m<10){
		cout<<":"<<0<<m;
	}else{
		cout<<":"<<m;
	}
	return 0;
}