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: // Author : RegalBeast
  
  import java.io.*;
  import java.util.*;
  import java.util.concurrent.*;
  
  public class Main implements Runnable {
    static Input in = new Input();
    static PrintWriter out = Output();
    
    public static void main(String[] args) {
      new Thread(null, new Main(), "King", 1<<25).start();
    }
  
    public void run() {
      int tests = in.nextInt();
      for (int t = 0; t < tests; t++) {
        int aw = in.nextInt();
        int bw = in.nextInt();
        
        int[] breaks = getBreaks(aw, bw);
        out.println(breaks.length);
        for (var val : breaks) {
          out.print(val + " ");
        }
        out.println();
      }
  
      in.close();
      out.close();
    }
  
    static int[] getBreaks(int aw, int bw) {
      Set<Integer> possible = new TreeSet<Integer>();
      int games = aw + bw;
      Set<Integer> borysServes = new HashSet<Integer>();
      borysServes.add(games>>1);
      borysServes.add((games+1)>>1);
      
      for (var bs : borysServes) {
        int as = games - bs;
        for (int bwa = 0; bwa <= bw; bwa++) {
          if (bwa > as) {
            break;
          }
          int bwb = bw - bwa;
          int awa = as - bwa;
          if (awa > aw) {
            continue;
          }
          int awb = aw - awa;
          if (bwb + awb <= bs && awa + bwa <= as) {
            possible.add(bs - bw + (bwa<<1));
          }
        }
      }
  
      int[] breaks = new int[possible.size()];
      int i = 0;
      for (var count : possible) {
        breaks[i++] = count;
      }
      return breaks;
    }
    
    static PrintWriter Output() {
      return new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
    }
    
    static PrintWriter Output(String fileName) {
      PrintWriter pw = null;
      try {
        pw = new PrintWriter(new BufferedWriter(new FileWriter(fileName)));
      } catch (IOException ex) {
        ex.printStackTrace();
      }
      return pw;
    }
  }
  
  class Input {
    BufferedReader br;
    StringTokenizer st;
    public Input() {
      br = new BufferedReader(new InputStreamReader(System.in));
    }
  
    public Input(String fileName) {
      try {
        br = new BufferedReader(new FileReader(fileName));
      } catch (IOException ex) {
        ex.printStackTrace();
      }
    }
  
    public String next() {
      while (st == null || !st.hasMoreElements()) {
        try {
          st = new StringTokenizer(br.readLine());
        } catch (IOException ex) {
          ex.printStackTrace();
        }
      }
      return st.nextToken();
    }
  
    public int nextInt() {
      return Integer.parseInt(next());
    }
  
    public long nextLong() {
      return Long.parseLong(next());
    }
  
    public Float nextFloat() {
      return Float.parseFloat(next());
    }
  
    public Double nextDouble() {
      return Double.parseDouble(next());
    }
  
    public String nextLine() {
      if (st != null && st.hasMoreElements()) {
        StringBuilder sb = new StringBuilder();
        while (st.hasMoreElements()) {
          sb.append(next());
        }
        return sb.toString();
      }
  
      String str = null;
      try {
        str = br.readLine();
      } catch (IOException ex) {
        ex.printStackTrace();
      }
      return str;
    }
  
    public void close() {
      try {
        br.close();
      } catch (IOException ex) {
        ex.printStackTrace();
      }
    }
  }
  