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 {
  
      static InputReader sc = new InputReader(System.in);
      static PrintWriter out = new PrintWriter(System.out);
  
      public static void main(String[] args) throws IOException {
          int t = sc.nextInt();
  
          while(t -- > 0){
  
  
              int a = sc.nextInt();
              int b = sc.nextInt();
  
              Set<Integer> possible = new TreeSet<>();
  
              int n = a + b;
  
              int nA = n/2, nB = n - nA;
              addPossibleCase(nA, nB, a, b, possible);
              if(n % 2 == 1){
                  addPossibleCase(nA + 1, nB - 1, a, b, possible);
              }
  
              out.println(possible.size());
  
              Iterator<Integer> itr = possible.iterator();
              while(itr.hasNext()){
                  out.print(itr.next() + " ");
              }
              out.println("");
          }
  
          out.flush();
          out.close();
      }
  
      static void addPossibleCase(int nA, int nB, int a, int b, Set<Integer> possible){
          int base = Math.abs(nA - a);
          if(nA >= a){
              for(int i = 0 ; i <= Math.min(a, nB); i++){
                  possible.add(base + i * 2);
              }
          }else{
              for(int i = 0 ; i <= nB - (a - nA); i++){
                  possible.add(base + i * 2);
              }
          }
  
      }
  
      static class InputReader {
          BufferedReader reader;
          StringTokenizer tokenizer;
  
          public InputReader(InputStream stream) {
              reader = new BufferedReader(new InputStreamReader(stream), 32768);
              tokenizer = null;
          }
  
  
          String next() {
              while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                  try {
                      tokenizer = new StringTokenizer(reader.readLine());
                  } catch (IOException e) {
                      throw new RuntimeException(e);
                  }
              }
              return tokenizer.nextToken();
          }
  
          int nextInt() {
              return Integer.parseInt(next());
          }
  
          long nextLong() {
              return Long.parseLong(next());
          }
  
          double nextDouble() {
              return Double.parseDouble(next());
          }
  
          String nextLine() {
              String str = "";
              try {
                  str = reader.readLine();
              } catch (IOException e) {
                  throw new RuntimeException(e);
              }
              return str;
          }
      }
  
      public static void shuffle(int[] a) {
          Random get = new Random();
          for (int i = 0; i < a.length; i++) {
              int r = get.nextInt(a.length);
              int temp = a[i];
              a[i] = a[r];
              a[r] = temp;
          }
      }
  
      public static void shuffle(long[] a) {
          Random get = new Random();
          for (int i = 0; i < a.length; i++) {
              int r = get.nextInt(a.length);
              long temp = a[i];
              a[i] = a[r];
              a[r] = temp;
          }
      }
  }
  