#include <stdio.h>

#include<stdio.h>
int main()
{
    int h = 0;
    int m = 0;
    int k = 0;
    scanf("%d:%d %d",&h,&m,&k);
    h = h+(m+k)/60;
    m = (k+m)%60;
    printf("%#02d:%#02d",h%24,m);
    return 0;
}