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 whatever //do not write package name here */
  
  import java.io.*;
  import java.util.*;
  public class GFG {
  	public static void main (String[] args) {
  		Scanner scn = new Scanner(System.in);
  		int t = scn.nextInt();
  		while(t-- > 0){
  		    int a = scn.nextInt();
  		    int b = scn.nextInt();
  		    
  		    int x = Math.max(a,b);
  		    int y = Math.min(a,b);
  		    
  		    int diff = x - y;
  		    int common = x - diff;
  		    
  		    ArrayList<Integer> al = new ArrayList<>();
  		    
  		    if(diff % 2 == 0){
  		        int half = diff/2;
  		        for(int i=0; i<=common; i++){
  		            int num = half + (i * 2);
  		            al.add(num);
  		        }
  		    }
  		    else{
  		        int half1 = diff/2, half2 = diff/2 + 1;
  		        for(int i=0; i<=common; i++){
  		            int num1 = half1 + (i * 2);
  		            al.add(num1);
  		            int num2 = half2 + (i * 2);
  		            al.add(num2);
  		        }
  		    }
  		    
  		    
  		    
  		    Collections.sort(al);
  		    int size = al.size();
  		    System.out.println(size);
  		    for(int i=0; i<size; i++){
  		        System.out.print(al.get(i) + " ");
  		    }
  		    System.out.println();
  		    
  		  //  int[] arr = new int[n];
  		  //  for(int i=0; i<n; i++){
  		  //      arr[i] = scn.nextInt();
  		  //  }
  		    
  		    
  		    
  		}
  	}
  }