题解 | #小乐乐定闹钟#

#include <stdio.h>

int main() {
    int min = 0;
    int hour = 0;
    int k = 0;
    
    while (3 == scanf("%d:%d %d", &hour, &min, &k))
    {
        printf("%02d:%02d\n", (hour + (k / 60) + (min + k % 60) / 60) % 24, (min + (k % 60)) % 60);
    }

    return 0;
}