#include <bits/stdc++.h>
using namespace std;
int main()
{
    int a,b,num;
    cin >>a>>b;
    int c=a/b+10,d;
    if (c>=60)
    {
        int mmm=floor(c/60);
        cout<<mmm;
        d=8-mmm;
        num=59-(c%60);
    }
    else
    {
        d=7;
        num=59-c;
    }
    if (num<10)
    {
        cout<<0<<d<<":"<<0<<num;
    }
    else
    {
        cout<<0<<d<<":"<<num;
    }
    return 0;
}