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.*;
  import java.util.*;
  
  public class Main {
      private static boolean isValid(int a, int b, int aa, int k) {
          int d = Math.abs(a-aa);
          return d <= k && (k-d)%2 == 0 && (k-d)/2 <= Math.min(a, b);
      }
      public static void main(String[] args) throws IOException {
          //BufferedReader f = new BufferedReader(new FileReader("uva.in"));
          BufferedReader f = new BufferedReader(new InputStreamReader(System.in));
          PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
          int t = Integer.parseInt(f.readLine());
          while(t-- > 0) {
              StringTokenizer st = new StringTokenizer(f.readLine());
              int a = Integer.parseInt(st.nextToken());
              int b = Integer.parseInt(st.nextToken());
              ArrayList<Integer> res = new ArrayList<>();
              for(int i = 0; i <= a+b; i++) {
                  if(isValid(a, b, (a+b+1)/2, i) || isValid(a, b, (a+b)/2, i)) {
                      res.add(i);
                  }
              }
              out.println(res.size());
              out.print(res.get(0));
              for(int i = 1; i < res.size(); i++) {
                  out.print(" " + res.get(i));
              }
              out.println();
          }
          f.close();
          out.close();
      }
  }