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 codechef; // don't place package name! */
  
  import java.util.*;
  import java.lang.*;
  import java.io.*;
  
  /* Name of the class has to be "Main" only if the class is public. */
  public class Main
  {
  	public static void main(String[] args) {
  		FastReader s = new FastReader();
  		PrintWriter out  = new PrintWriter(System.out);
  		//out.println();
  		int tc = s.nextInt();
  		while (tc-- > 0) {
  		    int a = s.nextInt();
  		    int b = s.nextInt();
  		    int d =  Math.abs(a-b)/2;
  		    ArrayList<Integer> al = new ArrayList<Integer>();
  		    if(((a+b)&1) == 0){
  		        for(int i = d ; i <= a+b-d ; i+=2){
  		            al.add(i);
  		        }
  		    }
  		    else{
  		        for(int i = d ; i <= a+b-d ; i++){
  		            al.add(i);
  		        }
  		    }
  		    out.println(al.size());
  		    for(int i : al){
  		        out.print(i+" ");
  		    }
  		    out.println();
  		}
  		out.flush();
  	}
  	
  	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;
  		}
  	}
  	
  	static int MOD = 1000000007;
  	
  	public static long power(long x,int y){
  	    long res = 1;
  	    
  	    x = x%MOD;
  	    
  	    while(y > 0){
  	        if((y&1) > 0)
  	            res = (res*x) % MOD;
  	            
  	        y = y >> 1;
  	        x = (x*x) % MOD;
  	    }
  	    
  	    return res;
  	}
  	
  	public static ArrayList<Integer> seive(int n){
  	    boolean[] isPrime = new boolean[n+1];
  	    
  	    Arrays.fill(isPrime,true);
  	    
  	    isPrime[0] = isPrime[1] = false;
  	    
  	    for(int i = 2 ; i * i <= n ; i++){
  	        if(isPrime[i]){
  	            for(int j = i*i ; j <= n ; j += i){
  	                isPrime[j] = false;
  	            }
  	        }
  	    }
  	    
  	    ArrayList<Integer> prime = new ArrayList<>();
  	    
  	    for(int i  = 0 ; i <= n ; i++){
  	        if(isPrime[i]){
  	            prime.add(i);        
  	        }
  	    }
  	    
  	    return prime;
  	}
  }
  