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: import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  
  public class B {
  
      static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      static final int N = 300005;
      static int[] f = new int[N];
  
      public static void main(String[] args) throws IOException {
          int t = Integer.parseInt(br.readLine());
          f[0] = 0;
          for(int i = 1; i < N; i++) {
              f[i] = i ^ f[i - 1];
          }
          while(t-- > 0) {
              solve();
          }
      }
  
      private static void solve() throws IOException {
          final String[] s = br.readLine().split(" ");
          int a = Integer.parseInt(s[0]), b = Integer.parseInt(s[1]);
          if(a == 1) {
              if(b == 0) {
                  System.out.println(1);
              } else if(b == 1) {
                  System.out.println(3);
              } else {
                  System.out.println(2);
              }
              return;
          }
          int res = a;
          if(f[a - 1] != b) {
              res++;
              if((f[a - 1] ^ b) == a) res++;
          }
          System.out.println(res);
      }
  }
  