#include<bits/stdc++.h>
using namespace std;
int main(){
	int sum = 10;
	int s,v,n,m;
	cin>>s>>v;
	n = s/v;
	if(s-n*v!=0) n++;
	sum+=n;
	if(sum<60){
		cout<<"07:";
		if(60-sum<10) cout<<"0"<<60-sum<<endl;
		else cout<<60-sum<<endl;	
	}
	else{
		m = sum/60;
		sum = sum-m*60;
		if(m>=8) cout<<8-m+23<<":";
		else cout<<"0"<<8-m<<":";
		if(60-sum<10) cout<<"0"<<60-sum<<endl;
		else cout<<60-sum<<endl;
	}
	return 0;
}