#include <stdio.h>
#include <math.h>
int main(void)
{
    double s,v,t;
    scanf("%lf %lf",&s,&v);
    t=s/v;
    int time=(int)ceil(t)+10;
    int hour=time/60;
    int minute=time%60;
    int HH=24+8-1-hour;
    int MM=60-minute;
    if (MM==60){
        HH++;
    }
    if (HH>24){
        HH=HH-24;
    }
    printf("%02d:%02d",HH,MM);
    return 0;



}