#include <iostream>
using namespace std;

int main()
{
    int s,v;
    int cnt;//总分钟数
    cin >> s>>v;
    if(s % v ==0)
    {
        cnt = s/v + 10;
    }
    else
    {
        cnt = s/v + 11;
    }
    int a;
    while(cnt >=60)
    {
        cnt -= 60;
        a++;
    }
    int c =a;
    a = 8 - a;
    cnt = 60 -cnt;
    if(a <0)
    {
        a = c+12;
    }    
    if(a < 10)
    {   
        
        cout << "0"<<a <<":"<<cnt<<endl;
    }
    else
    {
        cout << a<<":"<<cnt<<endl;
    }
    return 0;
}