#include <stdio.h>

int main()
{
    int h = 0;
    int m = 0;
    int k = 0;
    while (scanf("%d:%d %d", &h, &m, &k) == 3)
    {
        int i = 0;
        i = k / 60;
        k %= 60;    
        h += i;
        m += k;
        if (m > 59)
        {
            m -= 60;
            h++;
        }
        if (h > 23)
        {
            h %= 24;
        }
        printf("%02d:%02d", h, m);
    }


    return 0;
}