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.*;
  import java.util.Arrays;
  import java.util.Random;
  import java.util.StringTokenizer;
  
  public class codeforces742_B {
      private static int[] xorArr = getXor();
  
      private static void solve(FastIOAdapter io) {
          int a = io.nextInt();
          int b = io.nextInt();
  
          int xor = xorArr[a - 1];
          int need = xor ^ b;
          if (xor == b) {
              io.out.println(a);
          } else if (need == a) {
              io.out.println(a + 2);
          } else {
              io.out.println(a + 1);
          }
      }
  
      private static int[] getXor() {
          int[] res = new int[300001];
          res[0] = 0;
          for (int i = 1; i < res.length; i++) {
              res[i] = i ^ res[i - 1];
          }
          return res;
      }
  
      public static void main(String[] args) throws Exception {
          try (FastIOAdapter ioAdapter = new FastIOAdapter()) {
              int count = 1;
              count = ioAdapter.nextInt();
              while (count-- > 0) {
                  solve(ioAdapter);
              }
          }
      }
  
      static void ruffleSort(int[] arr) {
          int n = arr.length;
          Random rnd = new Random();
          for (int i = 0; i < n; ++i) {
              int tmp = arr[i];
              int randomPos = i + rnd.nextInt(n - i);
              arr[i] = arr[randomPos];
              arr[randomPos] = tmp;
          }
          Arrays.sort(arr);
      }
  
      static class FastIOAdapter implements AutoCloseable {
          BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
          public PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter((System.out))));
          StringTokenizer st = new StringTokenizer("");
  
          String next() {
              while (!st.hasMoreTokens())
                  try {
                      st = new StringTokenizer(br.readLine());
                  } catch (IOException e) {
                      e.printStackTrace();
                  }
              return st.nextToken();
          }
  
          int nextInt() {
              return Integer.parseInt(next());
          }
  
          int[] readArray(int n) {
              int[] a = new int[n];
              for (int i = 0; i < n; i++) a[i] = nextInt();
              return a;
          }
  
          long nextLong() {
              return Long.parseLong(next());
          }
  
          @Override
          public void close() throws Exception {
              out.flush();
              out.close();
              br.close();
          }
      }
  }