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.util.*;
  import java.lang.*;
  import java.io.*;
  
  // Created by @thesupremeone on 24/08/21
  public class B {
      void solve() throws IOException {
          int ts = getInt();
          for (int t = 1; t <= ts; t++){
              int a = getInt();
              int b = getInt();
              int max = Math.max(a, b);
              int min = Math.min(a, b);
              int minK = (max-min)/2;
              boolean even = (a+b)%2==0;
              int maxK = even ? minK+(2*min) :((max-min+1)/2)+(2*min);
              int inc = even ? 2 : 1;
              int count = (maxK-minK+1)/inc;
              if(even)count++;
              println(count);
              for (int i = minK; i <= maxK; i+=inc) {
                  print(i+" ");
              }
              println("");
          }
      }
  
      public static void main(String[] args) throws Exception {
          if (isOnlineJudge()) {
              in = new BufferedReader(new InputStreamReader(System.in));
              out = new BufferedWriter(new OutputStreamWriter(System.out));
              new B().solve();
              out.flush();
          } else {
              localJudge = new Thread();
              in = new BufferedReader(new FileReader("input.txt"));
              out = new BufferedWriter(new FileWriter("output.txt"));
              localJudge.start();
              new B().solve();
              out.flush();
              localJudge.suspend();
          }
      }
      static boolean isOnlineJudge(){
          try {
              return System.getProperty("ONLINE_JUDGE")!=null
                      || System.getProperty("LOCAL")==null;
          }catch (Exception e){
              return true;
          }
      }
      // Fast Input & Output
      static Thread localJudge = null;
      static BufferedReader in;
      static StringTokenizer st;
      static BufferedWriter out;
      static String getLine() throws IOException{
          return in.readLine();
      }
      static String getToken() throws IOException{
          if(st==null || !st.hasMoreTokens())
              st = new StringTokenizer(getLine());
          return st.nextToken();
      }
      static int getInt() throws IOException {
          return Integer.parseInt(getToken());
      }
      static long getLong() throws IOException {
          return Long.parseLong(getToken());
      }
      static void print(Object s) throws IOException{
          out.write(String.valueOf(s));
      }
      static void println(Object s) throws IOException{
          out.write(String.valueOf(s));
          out.newLine();
      }
  }