#include<stdio.h>
int main(void)
{
    int a,b;
    int min,hour;
    scanf("%d%d",&a,&b);
    min=a/b+1;
    hour=min/60;
    min=min%60;
    if((7-hour)>=0)
    {
        printf("%02d:%02d",7-hour,50-min);
    }
    else
    {
        hour=24-hour+7;
        printf("%d:%02d",hour,50-min);
    }
    return 0;
}