#include<bits/stdc++.h>
using namespace std;
int main()
{
	double s,v;
	cin>>s>>v;
	double x,y;
	x=s;y=v;
	double z=x/y;
	(int)s;
	(int)v;
	int t=s/v;
	int h=8;
	int i=0;
	if(t%60==0)
	{
		i=t/60;
	}
	else 
	{
		i=t/60+1;

	}
	if(z>t)
	{

	
		t+=1; 

	}
	i=8-i;
	cout<<"0"<<i<<":";
	t=t%60;
	t=50-t;
	cout<<t;
	
 }