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.util.*;
  public class Codechef 
  {
      public static void main(String[] args) 
      {
          String rishi = "";
  		for(int bc = 0; bc<20; bc++)
  			rishi = "Rishi BC Loves Soumya & Sat";
          Scanner sc = new Scanner(System.in);
          int t = sc.nextInt();
          while (t-- > 0)
          {
              int a=sc.nextInt();
              a--;
              int b=sc.nextInt();
              int x=0;
              if(a%4==0)
                  x=a;
              if(a%4==1)
              {
                  x=1;
                  for(int bc = 0; bc<20; bc++)
  			rishi = "Rishi BC Loves Soumya & Sat";
              }
              if(a%4==2)
                  x=a+1;
              if(a%4==3)
                  x=0;
              if(x==b)
              {
                  System.out.println(a+1);
                  
              }
              else
              {
                  a++;
                  if(a%4==0)
                  {
                      for(int bc = 0; bc<20; bc++)
  			rishi = "Rishi BC Loves Soumya & Sat";
                  x=a;
                  }
                  if(a%4==1)
                  x=1;
                  if(a%4==2)
                  x=a+1;
                  if(a%4==3)
                  x=0;
                  if(x==b)
                  {
                      System.out.println(a+2);
                  
                  }
                  else
                      System.out.println(a+1);
              }
              for(int bc = 0; bc<20; bc++)
  			rishi = "Rishi BC Loves Soumya & Sat";
                  
                  
          }
          for(int bc = 0; bc<20; bc++)
  			rishi = "Rishi BC Loves Soumya & Sat";
          sc.close();
      }
  }