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 {
  
      public static void solve(InputReader in, PrintWriter out) {
          int t = in.nextInt();
          while (t-- > 0) {
              int a = in.nextInt();
              int b = in.nextInt();
              int all = a + b;
              int diff = Math.abs(a - b) / 2;
              ArrayList<Integer> list = new ArrayList<>();
              if (all % 2 == 0) {
                  for (int i = diff; i <= all - diff; i += 2)
                      list.add(i);
              } else {
                  for (int i = diff; i <= all - diff; i++)
                      list.add(i);
              }
              out.println(list.size());
              for (Integer i : list)
                  out.print(i + " ");
              out.println();
          }
      }
  
      public static void main(String[] args) {
          InputStream inputStream;
          OutputStream outputStream;
          try {
              inputStream = new FileInputStream("input.txt");
              outputStream = new FileOutputStream("output.txt");
          } catch (Exception e) {
              inputStream = System.in;
              outputStream = System.out;
          }
  
          InputReader in = new InputReader(inputStream);
          PrintWriter out = new PrintWriter(outputStream);
  
          solve(in, out);
          out.close();
      }
  
      static class InputReader {
          public BufferedReader reader;
          public StringTokenizer tokenizer;
  
          public InputReader(InputStream stream) {
              reader = new BufferedReader(new InputStreamReader(stream), 32768);
              tokenizer = null;
          }
  
          public String nextToken() {
              while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                  try {
                      tokenizer = new StringTokenizer(reader.readLine());
                  } catch (IOException e) {
                      throw new RuntimeException(e);
                  }
              }
              return tokenizer.nextToken();
          }
  
          public int nextInt() {
              return Integer.parseInt(nextToken());
          }
  
          public long nextLong() {
              return Long.parseLong(nextToken());
          }
  
          public double nextDouble() {
              return Double.parseDouble(nextToken());
          }
  
          public int[] nextIntArr(int n) {
              int[] arr = new int[n];
              for (int i = 0; i < n; i++)
                  arr[i] = nextInt();
              return arr;
          }
      }
  }