#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,m,min=60,h=8,s=0,x=0;
    cin>>n>>m;
    s=n/m;
    if(n%m>0){
        s++;
    }
    if(s/60>0){
        h=h-s/60-1;
        s=s-(s/60)*60;
        min=min-s-10;
    }
    else{
        h=h-1;
        min=min-s-10;
    }
    if(min<0){
        h=h-1;
        x=min;
        min=min+x;
    }
    cout<<"0"<<h<<":"<<min;
    return 0;
}