#include<iostream>
#include<cstring>
#include<cstdio>
#include<algorithm>

using namespace std;

int get_seconds(int h,int m,int s)
{
    return h*3600+m*60+s;
}
int get_time()
{
    string line;
    getline(cin,line);
    if(line.back() != ')')  line +=" (+0)";

    int h1,m1,s1,h2,m2,s2,d;
    sscanf(line.c_str(),"%d:%d:%d %d:%d:%d (+%d)",&h1,&m1,&s1,&h2,&m2,&s2,&d);

    return get_seconds(h2,m2,s2) - get_seconds(h1,m1,s1) + d*24*3600;
}
int main()
{
    int n;
    scanf("%d",&n);
    getchar();
    while(n--)
    {
        int time = (get_time() + get_time()) / 2;
        int hour = time/3600, minute = time%3600/60, second=time%60;
        printf("%02d:%02d:%02d\n",hour,minute,second);
    }
    return 0;
}