#include<iostream>
#include<iomanip>
#include<math.h>
using namespace std;
int main()
{
    double s, v, t;
    cin >> s >> v;
    int H, num;
    t = s / v + 10;
    H = 7;
    num = t / 60;
    if (num)
    {
        H -= num;
        t -= 60 * num;
    }
    cout << setw(2) << setfill('0') << H << ":" << setw(2) << setfill('0') << 60 - ceil(t);
    return 0;
}