#include<bits/stdc++.h>
using namespace std;
int main(){
   int a,b,c,d;
   cin>>a>>b;
   if(a%b==0){
   	c=a/b+10; 
   }
   else{
   	c=a/b+1+10;
   }
   while(c>=60){
   	c-=60;
   	d+=1;
   }
   c=60-c;
   d=8-d;
   if(d<0){
   	d+=24;
   }
   if(d<10){
   	cout<<0;
   }
   cout<<d<<":";
   if(c<10){
   	cout<<0;
   }
   cout<<c;
   return 0;
}