codeforce - Middle of the Contest

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define MX 1e9+5
int main()
{
    int h1,h2,m1,m2;
    scanf("%d:%d",&h1,&m1);
    scanf("%d:%d",&h2,&m2);
    int h,m;
    int sum = h1*60+h2*60+m1+m2;
    sum/=2;
    h=sum/60;
    m=sum%60;
    if(h<10)printf("0");
    printf("%d:",h);
    if(m<10)printf("0");
    printf("%d\n",m);
    return 0;
}