1 #include <iostream>
 2 #include <algorithm>
 3 #include <cstring>
 4 #include <cstdio>
 5 #include <cmath>
 6 #include <stack>
 7 #include <set>
 8 #include <map>
 9 #include <queue>
10 #include <climits>
11 #define PI 3.1415926
12 
13 using namespace std;
14 const int MY_MAX = 1010;
15 int N;
16 
17 int main()
18 {
19     cin >>N;
20     while (N --)
21     {
22         int T;
23         map <string, int> my_map;
24         map <string, int> ::iterator iter;
25         pair <map<string, int> ::iterator, bool> pr;
26         scanf("%d", &T);
27         for (int i = 0; i < T; ++ i)
28         {
29             string my_str;
30             cin >>my_str;
31             pr = my_map.insert(pair<string, int>(my_str, 0));
32         }
33 
34         for (iter = my_map.begin(); iter != my_map.end(); ++ iter)
35         {
36             cout <<iter->first <<endl;
37             // printf("%s\n", iter->first);
38             // cannot pass objects of non-trivially-copyable type ‘const class std::basic_string<char>‘ through ‘...‘|
39             break;
40         }
41     }
42 }