#include<iostream>
using namespace std;

int s,v,m,n,l;
int main(){
	cin >>s>>v;
	m=s/v;
	if(s%v!=0) m++;
	n=470-m;
	if(n>=0){
		if(n%60<10) cout <<"0"<<n/60<<":"<<"0"<<n%60;
		else cout <<"0"<<n/60<<":"<<n%60;
	}
	else{
		l=24*60+n;
		if(l/60<10){
			if(l%60<10) cout <<"0"<<l/60<<":"<<"0"<<l%60;
			else cout <<"0"<<l/60<<":"<<l%60;
		} 
		else{
			if(l%60<10) cout <<l/60<<":"<<"0"<<l%60;
			else cout <<l/60<<":"<<l%60;
		}
		
	} 
	return 0;
}