description: Alice and Borys are playing tennis.
  
  A tennis match consists of games. In each game, one of the players is serving and the other one is receiving.
  
  Players serve in turns: after a game where Alice is serving follows a game where Borys is serving, and vice versa.
  
  Each game ends with a victory of one of the players. If a game is won by the serving player, it's said that this player holds serve. If a game is won by the receiving player, it's said that this player breaks serve.
  
  It is known that Alice won a games and Borys won b games during the match. It is unknown who served first and who won which games.
  
  Find all values of k such that exactly k breaks could happen during the match between Alice and Borys in total.
  
  Input
  
  Each test contains multiple test cases. The first line contains the number of test cases t (1 ≤ t ≤ 10^3). Description of the test cases follows.
  
  Each of the next t lines describes one test case and contains two integers a and b (0 ≤ a, b ≤ 10^5; a + b > 0) — the number of games won by Alice and Borys, respectively.
  
  It is guaranteed that the sum of a + b over all test cases does not exceed 2 ⋅ 10^5.
  
  Output
  
  For each test case print two lines.
  
  In the first line, print a single integer m (1 ≤ m ≤ a + b + 1) — the number of values of k such that exactly k breaks could happen during the match.
  
  In the second line, print m distinct integers k_1, k_2, …, k_m (0 ≤ k_1 < k_2 < … < k_m ≤ a + b) — the sought values of k in increasing order.
  
  Example
  
  Input
  
  
  3
  2 1
  1 1
  0 5
  
  
  Output
  
  
  4
  0 1 2 3
  2
  0 2
  2
  2 3
  
  Note
  
  In the first test case, any number of breaks between 0 and 3 could happen during the match: 
  
    * Alice holds serve, Borys holds serve, Alice holds serve: 0 breaks; 
    * Borys holds serve, Alice holds serve, Alice breaks serve: 1 break; 
    * Borys breaks serve, Alice breaks serve, Alice holds serve: 2 breaks; 
    * Alice breaks serve, Borys breaks serve, Alice breaks serve: 3 breaks. 
  
  
  
  In the second test case, the players could either both hold serves (0 breaks) or both break serves (2 breaks).
  
  In the third test case, either 2 or 3 breaks could happen: 
  
    * Borys holds serve, Borys breaks serve, Borys holds serve, Borys breaks serve, Borys holds serve: 2 breaks; 
    * Borys breaks serve, Borys holds serve, Borys breaks serve, Borys holds serve, Borys breaks serve: 3 breaks. 
solution: import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.util.*;
  
  public class Practice {
  
      public static void main(String[] args) throws IOException {
          Scanner sc = new Scanner(System.in);
          int t = sc.nextInt();
          StringBuilder sb = new StringBuilder();
          while (t-->0){
              int alice = sc.nextInt(); int bob = sc.nextInt();
              TreeSet<Integer> ans = new TreeSet<>();
              int serve1 = (alice+bob+1)/2;
              findBreaks(serve1, alice, bob, ans);
              sb.append(ans.size());
              sb.append("\n");
              for(int x : ans){
                  sb.append(x);
                  sb.append(" ");
              }
              sb.append("\n");
          }
          System.out.println(sb.toString().trim());
      }
  
      private static void findBreaks(int serve,  int alice, int bob, TreeSet<Integer> ans) {
          for (int i = 0; i <= serve; i++) {
              isValid(i, alice, bob, ans);
          }
      }
  
      private static void isValid(int aliceBreak, int alice, int bob, TreeSet<Integer> ans) {
          if(aliceBreak>alice) return;
          int serve1 = (alice+bob+1)/2; int serve2 = alice+bob-serve1;
          int num1 = isValidAll(serve1, serve2, aliceBreak, alice, bob);
          int num2 = isValidAll(serve2, serve1, aliceBreak, alice, bob);
          if(num1>=0 && num1<=bob){
              ans.add(aliceBreak+num1);
          }
  
          if(num2>=0 && num2<=bob){
              ans.add(aliceBreak+num2);
          }
      }
  
      private static int isValidAll(int aliceServe, int bobServe, int aliceBreak, int aliceWin, int bobWin) {
          int bobServeWinning = bobServe -aliceBreak;
          int bobBreaksValue = bobWin - bobServeWinning;
          int aliceServeWinning = aliceServe - bobBreaksValue;
  
          if(aliceBreak+aliceServeWinning != aliceWin || bobServeWinning +  bobBreaksValue != bobWin) return -1;
          return bobBreaksValue;
      }
  }