#include <iostream>
#include <cstdio>
#include <cmath>
using namespace std;
double s,v;
int t,h,m;
int main()
{
    cin >> s >> v;
    t = ceil(s/v)+10;//ceil函数是向上取整，在cmath库里
    h = (1920-t)/60;
    m = (1920-t)%60;
    if(h>=24) h-=24;
    if(h<10)printf("0%d:%d",h,m);
    else printf("%d:%d",h,m);
    return 0; 
}