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: 
  //package com.company;
  
  
  
  import  java.math.*;
  import java.net.Inet4Address;
  import java.util.*;
  import java.lang.*;
  import java.io.*;
  
  
  
  public final class Main {
  
      FastReader s;
  
  
      public static void main (String[] args) throws java.lang.Exception
      {
  
          new Main().run();
  
      }
      void run()
      {
          s = new FastReader();
          solve();
      }
      StringBuffer sb;
  
      void solve()
      {
  
          sb = new StringBuffer();
  
  
  
          for(int T = s.nextInt();T > 0;T--)
          {
  
              start();
  
          }
  
           System.out.print(sb);
  
      }
  
  
      void start()
      {
  
         int a = s.nextInt();
         int b = s.nextInt();
         if(a < b)
         {
             int t = a;
             a = b;
             b = t;
         }
          int diff=a-b;
         ArrayList<Integer> v = new ArrayList<>();
  
          for(int i=0;i<=2*b;i+=2) v.add(i);
          if(b==0) {
              v.remove(v.size()-1);
          };
          HashSet<Integer> x = new HashSet<>();
  
          if(diff%2 != 0){
              for(int i=0;i<v.size();i++){
                  x.add(v.get(i)+diff/2);
                  x.add(v.get(i)+diff/2+1);
              }
              x.add(diff/2);
              x.add(diff/2+1);
          }
          else {
              for(int i=0;i<v.size();i++){
                  //ans.insert(v[i]);
                  x.add(v.get(i)+diff/2);
              }
              x.add(diff/2);
          }
        ArrayList<Integer> pp = new ArrayList<>(x);
         Collections.sort(pp);
         sb.append(pp.size()+"\n");
         for(int i : pp)
         {
             sb.append(i+" ");
         }
         sb.append("\n");
      }
  
      int gcd(int a, int b)
      {
          if (b == 0)
              return a;
          return gcd(b, a % b);
      }
      long gcd(long a, long b)
      {
          if (b == 0)
              return a;
          return gcd(b, a % b);
      }
      long power(long x, long y, long p)
      {
          long res = 1; // Initialize result
  
          // Update x if it is more
          // than or equal to p
          x = x % p;
  
          while (y > 0)
          {
              // If y is odd, multiply
              // x with the result
              if ((y & 1) > 0)
                  res = (res * x) % p;
  
              // y must be even now
              y = y >> 1; // y = y/2
              x = (x * x) % p;
          }
          return res;
      }
  
      int lower_bound(int [] arr , int key)
      {
  
          int i = 0;
          int j = arr.length-1;
          //if(arr[i] > key)return -1;
          if(arr[j] < key)return -1;
  
          while(i<j)
          {
              int mid = (i+j)/2;
  
              if(arr[mid] == key)
              {
                  j = mid;
              }
  
              else if(arr[mid] < key)
              {
                  i = mid+1;
              }
              else
                  j = mid-1;
          }
  
          return i;
      }
  
      int upper_bound(int [] arr , int key)
      {
  
          int i = 0;
          int j = arr.length-1;
          if(arr[j] <= key)return j+1;
  
          while(i<j)
          {
              int mid = (i+j)/2;
  
  
  
              if(arr[mid] <= key)
              {
                  i = mid+1;
              }
              else
                  j = mid;
          }
  
          return i;
      }
  
      
  
      int find(int dsu [],int i)
      {
          if(dsu[i] == i)
              return i;
          dsu[i] = find(dsu,dsu[i]);
          return dsu[i];
      }
  
      void  union(int dsu[] ,int i, int j)
      {
          int a = find(dsu,i);
          int b = find(dsu,j);
          dsu[a] = b;
      }
  
      static void sort(int[] A){
          int n = A.length;
          Random rnd = new Random();
          for(int i=0; i<n; ++i){
              int tmp = A[i];
              int randomPos = i + rnd.nextInt(n-i);
              A[i] = A[randomPos];
              A[randomPos] = tmp;
          }
          Arrays.sort(A);
      }
      static void sort(long[] A){
          int n = A.length;
          Random rnd = new Random();
          for(int i=0; i<n; ++i){
              long tmp = A[i];
              int randomPos = i + rnd.nextInt(n-i);
              A[i] = A[randomPos];
              A[randomPos] = tmp;
          }
          Arrays.sort(A);
      }
      static String sort(String s) {
          Character ch[]=new Character[s.length()];
          for(int i=0;i<s.length();i++) {
              ch[i]=s.charAt(i);
          }
          Arrays.sort(ch);
          StringBuffer st=new StringBuffer("");
          for(int i=0;i<s.length();i++) {
              st.append(ch[i]);
          }
          return st.toString();
      }
  
      //long array input
      public long [] longArr(int len)
      {
          // long arr input
          long [] arr = new long[len];
          String [] strs =  s.nextLine().trim().split("\\s+");
          for(int i =0; i<len; i++)
          {
              arr[i] = Long.parseLong(strs[i]);
  
          }
          return arr;
      }
      // int arr input
      public int [] intArr(int len)
      {
          // long arr input
          int [] arr = new int[len];
          String [] strs =  s.nextLine().trim().split("\\s+");
          for(int i =0; i<len; i++)
          {
              arr[i] = Integer.parseInt(strs[i]);
  
          }
          return arr;
      }
  
      static class FastReader
      {
          BufferedReader br;
          StringTokenizer st;
  
          public FastReader()
          {
              br = new BufferedReader(new
                      InputStreamReader(System.in));
          }
  
          String next()
          {
              while (st == null || !st.hasMoreElements())
              {
                  try
                  {
                      st = new StringTokenizer(br.readLine());
                  }
                  catch (IOException  e)
                  {
                      e.printStackTrace();
                  }
              }
              return st.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 = br.readLine();
              }
              catch (IOException e)
              {
                  e.printStackTrace();
              }
              return str;
          }
      }
  
  
  
  }
  