# include <iostream>
using namespace std;
int a,b,c,d,e;
int main()
{
 cin>>a;//距离 
 cin>>b; //速度 
if(a%b!=0)	
{c=a/b+11;}
else
{c=a/b+10;}
if(c%60!=0)
{d=c/60+1;}
else
{d=c/60;}
e=c%60;
if(d<=8)
{if(e>50)
{cout<<0<<8-d<<":"<<0<<60-e;}
else
{cout<<0<<8-d<<":"<<60-e;}}
else
{
if(e>50)
{cout<<0<<8-d<<":"<<0<<60-e;}
else
{cout<<24-d<<":"<<60-e;
}}
return 0;	
	
 }