#include <stdio.h>
int main()
{
    int m,h,k,t1,t2;
    scanf("%02d:%02d %d",&t1,&t2,&k);
    h=((t2+k)/60+t1)%24;
    m=(t2+k)%60;
    printf("%02d:%02d",h,m);
    return 0;
}