#include<bits/stdc++.h>
using namespace std;
int main()
{
    int a,b,c = 0,d = 8,e = 0;
    cin >> a >> b;
    c += 10;
    c += a / b;
    if(a % b != 0)
    {
        c++;
    }
    d -= c / 60;
    if(c % 60 != 0)
    d--;
    if(d <= 0)
    d = 24 + d;
    for(int i = 0;i <= 10000;i++)
    {
        if(c >= 60)
        c -= 60;
    }
    cout << d << ":" << 60 - c;
}