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.*;
  import java.io.*;
  
  public class MEX_Or_Mixup {
  
  	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;
  		}
  
  	}
  
  	public static void shuffle(int[] a) {
  		Random r = new Random();
  
  		for (int i = 0; i <= a.length - 2; i++) {
  			int j = i + r.nextInt(a.length - i);
  
  			swap(a, i, j);
  		}
  
  		Arrays.sort(a);
  	}
  
  	public static void swap(int[] a, int i, int j) {
  		int temp = a[i];
  		a[i] = a[j];
  		a[j] = temp;
  	}
  
  	public static void main(String[] args) {
  		// TODO Auto-generated method stub
  		FastReader t = new FastReader();
  		PrintWriter o = new PrintWriter(System.out);
  		int test = t.nextInt();
  		int[] xor = new int[300000];
  
  		for (int i = 1; i < xor.length; ++i)
  			xor[i] = xor[i - 1] ^ i;
  
  		while (test-- > 0) {
  			int a = t.nextInt();
  			int b = t.nextInt();
  
  			if (xor[a - 1] == b)
  				o.println(a);
  			else if ((b ^ xor[a - 1]) != a)
  				o.println(a + 1);
  			else
  				o.println(a + 2);
  
  		}
  
  		o.flush();
  		o.close();
  	}
  }
  