#include<bits/stdc++.h>
using namespace std;
int main(){
	float s,v;
	int a,sum,b;
    cin>>s>>v;
    sum=ceil(s/v);
    a=ceil(s/v/60);
    if(a==s/v/60)
    a=a+1;
    b=sum%60;
    if(a<=8&&50-b>=10)
    cout<<"0"<<8-a<<":"<<50-b;
    if(a<=8&&50-b<10)
    cout<<"0"<<8-a<<":"<<"0"<<50-b;
    if(a>8&&50-b>=10){
    	if(32-a<10)
    cout<<"0"<<32-a<<":"<<50-b;
    else
    cout<<32-a<<":"<<50-b;
}
    if(a>8&&50-b<10){
    if(32-a<0)
    cout<<"0"<<32-a<<":"<<"0"<<50-b;
    else
    cout<<32-a<<":"<<"0"<<50-b;
}
    return 0;
}