#include <iostream>
using namespace std;
int main()
{
	int s,u,a,n=8;
	cin>>s>>u;
	if(s%u==0)
	{
		a=s/u+10;
	}
	else
	{
		a=s/u+10+1;
	}
	s=a/60;
	u=a%60; 
	cout<<'0';
	if(u!=0)
	{
		if(60-u<10)
		{
			if(8-s-1<0) cout<<24+8-s-1<<":0"<<60-u;
			else cout<<8-s-1<<":0"<<60-u;
		}
		else
		{
			if(8-s-1<0) cout<<24+8-s-1<<':'<<60-u;
			else cout<<8-s-1<<':'<<60-u;
		}
	}
	else
	{
		if(8-s<0) cout<<24+8-s<<':'<<"00";
		else cout<<8-s<<':'<<"00";
	}
	cout<<endl;
	return 0;
}

竟然错了