description: Alice gave Bob two integers a and b (a > 0 and b ≥ 0). Being a curious boy, Bob wrote down an array of non-negative integers with \operatorname{MEX} value of all elements equal to a and \operatorname{XOR} value of all elements equal to b.
  
  What is the shortest possible length of the array Bob wrote?
  
  Recall that the \operatorname{MEX} (Minimum EXcluded) of an array is the minimum non-negative integer that does not belong to the array and the \operatorname{XOR} of an array is the [bitwise XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of all the elements of the array.
  
  Input
  
  The input consists of multiple test cases. The first line contains an integer t (1 ≤ t ≤ 5 ⋅ 10^4) — the number of test cases. The description of the test cases follows.
  
  The only line of each test case contains two integers a and b (1 ≤ a ≤ 3 ⋅ 10^5; 0 ≤ b ≤ 3 ⋅ 10^5) — the \operatorname{MEX} and \operatorname{XOR} of the array, respectively.
  
  Output
  
  For each test case, output one (positive) integer — the length of the shortest array with \operatorname{MEX} a and \operatorname{XOR} b. We can show that such an array always exists.
  
  Example
  
  Input
  
  
  5
  1 1
  2 1
  2 0
  1 10000
  2 10000
  
  
  Output
  
  
  3
  2
  3
  2
  3
  
  Note
  
  In the first test case, one of the shortest arrays with \operatorname{MEX} 1 and \operatorname{XOR} 1 is [0, 2020, 2021].
  
  In the second test case, one of the shortest arrays with \operatorname{MEX} 2 and \operatorname{XOR} 1 is [0, 1].
  
  It can be shown that these arrays are the shortest arrays possible.
solution:   /* package codechef; // don't place package name! */
  import java.util.*;
  import java.lang.*;
  import java.io.*;
  import java.math.BigInteger;
  
  /* Name of the class has to be "Main" only if the class is public. */
  public class hello
  {
       static class Pair implements Comparable<Pair>{
          int power=0;
          int bonus=0;
          public Pair(int power,int bonus){
              this.power=power;
              this.bonus=bonus;
          }
          public int compareTo(Pair o){
              return this.power-o.power;
          }
      }
       static class FastReader 
      { 
          BufferedReader br; 
          StringTokenizer st; 
    
          public FastReader() 
          { 
              try {
                 br=new BufferedReader(new FileReader("input.txt"));
                 PrintStream out= new PrintStream(new FileOutputStream("output.txt"));
                 System.setOut(out);
              }
    
              // Catch block to handle the exceptions
              catch (Exception e) {
                  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 computeXOR(int n)
      {
          // If n is a multiple of 4
          if (n % 4 == 0)
              return n;
        
          // If n%4 gives remainder 1
          if (n % 4 == 1)
              return 1;
        
          // If n%4 gives remainder 2
          if (n % 4 == 2)
              return n + 1;
        
          // If n%4 gives remainder 3
          return 0;
      }
      public static void main (String[] args) throws java.lang.Exception
      {
  
         try{
          FastReader sc=new FastReader();
          BufferedWriter out = new BufferedWriter(
              new OutputStreamWriter(System.out));
          int t=sc.nextInt();
          while(t-->0){
  
              int a = sc.nextInt();
              int b = sc.nextInt();
  
              int k= computeXOR(a-1);
              k = k ^ 0;
              if(k==b)
                  System.out.println(a);
              else if((k^a)==b)
                  System.out.println(a+2);
              else
                  System.out.println(a+1);
  
          }
      }catch(Exception e){
              return;
          }
      }
  }