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.*;
  
  public class B {
  	public static void main(String[] args) {
  		Scanner sc = new Scanner(System.in);
  		int t=sc.nextInt();
  		while(t-->0) {
  			long a=sc.nextLong();
  			long b=sc.nextLong();
  			long sum=a+b;
  			Set<Long> st= new HashSet<Long>();
  			
  			if((sum%2)==0) {
  				long max=Math.max(a,b);
  				long min= Math.min(a,b);
  				long servings=sum/2;
  				long temp=(max-servings);
  //				System.out.println(temp+" YES1!!!");
  				for(long i=0;i<=min;i++) {
  					st.add(temp);
  					temp+=2;
  				}
  			}
  			else {
  				long max=Math.max(a,b);
  				long min= Math.min(a,b);
  				long servings1=sum/2;
  				long servings2=(sum/2)+1;
  				long temp1=(max-servings1);
  				long temp2=max-servings2;
  //				System.out.println(temp1+ " "+temp2+" "+ "YES2!!!");
  				for(long i=0;i<=min;i++) {
  					st.add(temp1);
  					temp1+=2;
  				}
  				
  				for(long i=0;i<=min;i++) {
  					st.add(temp2);
  					temp2+=2;
  				}
  			}
  			
  			System.out.println(st.size());
  			List<Long> al= new ArrayList<>();
  			
  			for (Long l : st) {
  			    al.add(l);
  			}
  			
  			Collections.sort(al);
  			for(int i=0;i<al.size();i++) {
  				System.out.print(al.get(i)+" ");
  			}
  			System.out.println();
  			
  			
  					
  			
  			
  			
  		}
  	}
  }
  