#include<bits/stdc++.h>
using namespace std;

int s,v;

int main()
{
	cin>>s>>v;
	int shi,fen;
	shi=7;
	fen=50;
	if(s%v==0)
	{
		shi-=s/v/60;
		s=s/v/60;
		fen-=s;
	}
	else
	{
		shi-=(s/v+1)/60;
		s=(s/v+1)%60;
		fen-=s;
	}
	cout<<'0'<<shi<<':'<<fen;
	return 0;
}