description: Vlad has n friends, for each of whom he wants to buy one gift for the New Year.
  
  There are m shops in the city, in each of which he can buy a gift for any of his friends. If the j-th friend (1 ≤ j ≤ n) receives a gift bought in the shop with the number i (1 ≤ i ≤ m), then the friend receives p_{ij} units of joy. The rectangular table p_{ij} is given in the input.
  
  Vlad has time to visit at most n-1 shops (where n is the number of friends). He chooses which shops he will visit and for which friends he will buy gifts in each of them.
  
  Let the j-th friend receive a_j units of joy from Vlad's gift. Let's find the value α=min\\{a_1, a_2, ..., a_n\}. Vlad's goal is to buy gifts so that the value of α is as large as possible. In other words, Vlad wants to maximize the minimum of the joys of his friends.
  
  For example, let m = 2, n = 2. Let the joy from the gifts that we can buy in the first shop: p_{11} = 1, p_{12}=2, in the second shop: p_{21} = 3, p_{22}=4.
  
  Then it is enough for Vlad to go only to the second shop and buy a gift for the first friend, bringing joy 3, and for the second — bringing joy 4. In this case, the value α will be equal to min\{3, 4\} = 3
  
  Help Vlad choose gifts for his friends so that the value of α is as high as possible. Please note that each friend must receive one gift. Vlad can visit at most n-1 shops (where n is the number of friends). In the shop, he can buy any number of gifts.
  
  Input
  
  The first line of the input contains an integer t (1 ≤ t ≤ 10^4) — the number of test cases in the input.
  
  An empty line is written before each test case. Then there is a line containing integers m and n (2 ≤ n, 2 ≤ n ⋅ m ≤ 10^5) separated by a space — the number of shops and the number of friends, where n ⋅ m is the product of n and m.
  
  Then m lines follow, each containing n numbers. The number in the i-th row of the j-th column p_{ij} (1 ≤ p_{ij} ≤ 10^9) is the joy of the product intended for friend number j in shop number i.
  
  It is guaranteed that the sum of the values n ⋅ m over all test cases in the test does not exceed 10^5.
  
  Output
  
  Print t lines, each line must contain the answer to the corresponding test case — the maximum possible value of α, where α is the minimum of the joys from a gift for all of Vlad's friends.
  
  Example
  
  Input
  
  
  5
  
  2 2
  1 2
  3 4
  
  4 3
  1 3 1
  3 1 1
  1 2 2
  1 1 3
  
  2 3
  5 3 4
  2 5 1
  
  4 2
  7 9
  8 1
  9 6
  10 8
  
  2 4
  6 5 2 1
  7 9 7 2
  
  
  Output
  
  
  3
  2
  4
  8
  2
solution: //package practice.codeforces.round762;
  
  import java.util.*;
  
  // https://codeforces.com/contest/1619/problem/D
  public class D {
      public static void main(String[] args) {
  
  
          Scanner scanner = new Scanner(System.in);
          int t = scanner.nextInt();
          for (int i = 0; i < t; i++) {
              int m = scanner.nextInt();
              int n = scanner.nextInt();
              PriorityQueue<int[]> queue = new PriorityQueue<>(Comparator.comparingInt(arr -> -arr[2]));
              for (int j = 0; j < m; j++) {
                  for (int k = 0; k < n; k++) {
                      int[] tuple = {j, k, scanner.nextInt()};
                      queue.add(tuple);
                  }
              }
              System.out.println(findMaxJoy(queue, n));
          }
      }
  
      private static int findMaxJoy(PriorityQueue<int[]> queue, int n) {
          Set<Integer> friends = new HashSet<>();
          Map<Integer, Set<Integer>> friendsInAShop = new HashMap<>();
          Set<Integer> severalFriends = new HashSet<>();
          while (!queue.isEmpty()) {
              int[] tuple = queue.poll();
              int friend = tuple[1];
              int shop = tuple[0];
  
              Set<Integer> inShop;
              if (friendsInAShop.containsKey(shop)) {
                  inShop = friendsInAShop.get(shop);
                  severalFriends.add(shop);
              } else {
                  inShop = new HashSet<>();
                  friendsInAShop.put(shop, inShop);
              }
              inShop.add(friend);
  
  
              friends.add(friend);
              boolean hasAShopWithSeveralFriends = false;
              for (int sh : severalFriends) {
                  if (shop == sh || friendsInAShop.get(sh).size() > 2 || !friendsInAShop.get(sh).contains(friend)) {
                      hasAShopWithSeveralFriends = true;
                      break;
                  }
              }
              if (hasAShopWithSeveralFriends && friends.size() == n) {
                  return tuple[2];
              }
          }
          return 0;
      }
  
  //    private static void decreaseKey(Map<Integer, Integer> map, int key) {
  //        int newValue = map.get(key) - 1;
  //        if (newValue == 0) {
  //            map.remove(key);
  //        } else {
  //            map.put(key, newValue);
  //        }
  //    }
  //
  //    private static void increaseKey(Map<Integer, Integer> map, int key) {
  //        map.put(key, map.getOrDefault(key, 0) + 1);
  //    }
  }
  