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.math.BigInteger;
  import java.util.*;
  import java.io.*;
  
  public class B_MEXor_Mixup {
      public static void main (String[] args) {
          FastReader scan = new FastReader();
          int t = scan.nextInt();
          int[] arr = new int[300001];
          for (int i=1; i<=300000; i++) {
              arr[i] = (arr[i-1] ^ i);
          }
          while (t-- > 0) {
              int a = scan.nextInt(), b = scan.nextInt();
              int xor = arr[a-1];
              if (xor == b)
                  System.out.println(a);
              else {
                  if ((xor ^ b) == a)
                      System.out.println(a+2);
                  else
                      System.out.println(a+1);
              }
          }
      }
      public static void inputArray (int[] arr, int n, FastReader scan) {
          for (int i=0; i<n; i++) {
              arr[i] = scan.nextInt();
          }
      }
      public static void printArray (int[] arr) {
          for (int i=0; i<arr.length; i++) {
              System.out.print(arr[i] + " ");
          }
          System.out.println();
      }
      public static boolean isPrime (int n) {
          if (n <= 1)
              return false;
          if (n <= 3)
              return true;
          if (n % 2 == 0 || n % 3 == 0)
              return false;
          for (int i = 5; i * i <= n; i = i + 6)
              if (n % i == 0 || n % (i + 2) == 0)
                  return false;
          return true;
      }
      public static int gcd (int a, int b) {
          BigInteger a1 = BigInteger.valueOf(a);
          BigInteger b1 = BigInteger.valueOf(b);
          return a1.gcd(b1).intValue();
      }
      public static int numberOfDigitsInNumber (int n) {
          return (int)Math.floor(Math.log10(n)) + 1;
      }
      public static boolean isPowerOfTwo (int x) {
          return x!=0 && ((x&(x-1)) == 0);   
      }
      public static String toBinaryString (int n) {
          return Integer.toString(n, 2);
          // for other bases change 2 to other bases
      }
      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;
          }
      }
  }
  
  // For IO using Files
  // public static void main throws IOException
  // BufferedReader br = new BufferedReader(new FileReader("input.txt"));
  // PrintWriter pw = new PrintWriter(new BufferedWriter(new FileWriter("output.txt")));
  // String st[]=br.readLine().split(" ");
  // int n=Integer.parseInt(st[0]);
  // int m=Integer.parseInt(st[1]);
  // at the end
  // br.close(); pw.close();
  // for printing pw.println(), pw.print(), etc...
  // for arrays : int arr[] = Arrays.stream(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();