题解 | #小乐乐定闹钟#

#include<iostream>
using namespace std;
int main(){
    int a,b,c;
    scanf("%d:%d %d",&a,&b,&c);
    int h,f;
    h=c/60;
    f=c%60;
    a=(a+h+(b+f)/60)>=24?(a+h+(b+f)/60)%24:(a+h+(b+f)/60);
    b=(b+f)>=60?((b+f)%60):(b+f);
     printf("%02d:%02d",a,b);
    return 0;
}