#include <stdio.h>

int main() {
    int h,m,k,x,y;
    scanf("%d:%d %d",&h,&m,&k);
    x=((k+m)/60+h)%24;//超过1天时
    y=(k+m)%60;
    printf("%#02d:%#02d",x,y);
    return 0;
}