#include <iostream>
#include <cstdio>
#include <cmath>
using namespace std;

int main()
{
    int s, v, t, g;
    cin >> s >> v;
    t = ceil(s / v);
    t += 10;
    g = 60 - t;
    long long h,m;
    h = t / 60 - 24;
    m = t % 60;
    if(h < 10)
        cout << 0 << h << ":";
    else
        cout << h << ":";
    
    if(m < 10)
        cout << 0 <<m;
    else
        cout << m;
    return 0;
}