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.io.*;
  import java.util.*;
  
  public class CharmedByTheGame {
  	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
  	static StringTokenizer st;
  	
  	public static void main(String[] args) throws IOException {
  		int t = readInt();
  		
  		while (t-- > 0) {
  			int a = readInt(), b = readInt(), n = a + b;
  			boolean[] vis = new boolean[n + 1];
  			int spotsA = n / 2, spotsB = n / 2;
  			if (n % 2 == 1) spotsA ++;
  			for (int i = 0; i <= b; i ++) {
  				if (i <= spotsA) {
  					if (spotsB >= b - i) vis[i + spotsB - (b - i)] = true;
  				} else vis[spotsA + spotsB - (b - spotsA)] = true;
  				
  				if (i <= spotsB) {
  					if (spotsA >= b - i) vis[i + spotsA - (b - i)] = true;
  				} else vis[spotsB + spotsA - (b - spotsB)] = true;
  			}
  			Queue<Integer> q = new LinkedList<Integer>();
  			int cnt = 0;
  			for (int i = 0; i <= n; i ++) if (vis[i]) { q.add(i); cnt ++; }
  			System.out.println(cnt);
  			while (!q.isEmpty()) System.out.print(q.poll() + " ");
  			System.out.println();
  		}
  	}
  
  	static String next() throws IOException {
  		while (st == null || !st.hasMoreTokens()) 
  			st = new StringTokenizer(br.readLine().trim());
  		return st.nextToken();
  	}
  	static long readLong() throws IOException {
  		return Long.parseLong(next());
  	}
  	static int readInt() throws IOException {
  		return Integer.parseInt(next());
  	}
  	static double readDouble() throws IOException {
  		return Double.parseDouble(next());
  	}
  	static char readCharacter() throws IOException {
  		return next().charAt(0);
  	}
  	static String readLine() throws IOException {
  		return br.readLine().trim();
  	}
  }