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: //Input
  import java.util.Scanner;
  import java.io.BufferedReader;
  import java.io.InputStreamReader;
  //Output
  import java.io.PrintWriter;
  //DataStructure
  import java.util.Arrays;
  import java.util.ArrayList;
  import java.util.LinkedList;
  import java.util.Vector;
  import java.util.Map;
  import java.util.HashMap;
  import java.util.TreeMap;
  import java.util.LinkedHashMap;
  import java.util.HashSet;
  import java.util.TreeSet;
  import java.util.LinkedHashSet;
  import java.util.Collections;
  import java.util.Collection;
  //Maths
  import static java.lang.Math.abs;
  import static java.lang.Math.ceil;
  import static java.lang.Math.floor;
  import static java.lang.Math.max;
  import static java.lang.Math.min;
  
  public class codeB {
  
      public static void main(String[] args) throws Exception {
          BufferedReader sc = new BufferedReader(new InputStreamReader(System.in));
          long xorArr[] = new long[300000+1];
          xorArr[0] = 0;
          xorArr[1] = 1;
          for(int i = 2; i < xorArr.length; i++){
              xorArr[i] = i^xorArr[i-1];
          }
          
          int testCase = Integer.parseInt(sc.readLine());
          while (testCase-- > 0) {
              String s[] = sc.readLine().split(" ");
              int a = Integer.parseInt(s[0]);
              int b = Integer.parseInt(s[1]);
              if(xorArr[a-1]==b){
                  System.out.println(a);
              }
              else if((xorArr[a-1]^b)!=a){
                  System.out.println(a+1);
              }
              else{
                  System.out.println(a+2);
              }
          }
      }
  }