#include <stdio.h>

int main() {
    int hour, minute, k, ret;
    //注意输入小时与分钟之间用 ：隔开
    while ((ret = scanf("%d:%d %d", &hour, &minute, &k)) != EOF) {
        hour = (hour + (k + minute) / 60) % 24;    //注意加上初始分钟数
        minute = (k + minute) % 60;

        printf("%02d:%02d\n", hour, minute);
    }

    return 0;
}