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