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: public class B {
  
  	public Object solve () {
  		int A = sc.nextInt(), B = sc.nextInt();
  
  		int Y = X[A-1] ^ B;
  
  		if (Y == 0)
  			return A;
  
  		if (Y != A)
  			return A + 1;
  
  		return A + 2;
  	}
  
  	private static final int CONTEST_TYPE = 2;
  
  	static int Z = 300010;
  	static int [] X = new int [Z];
  
  	private static void init () {
  		for (int i : rep(1, Z))
  			X[i] = X[i-1] ^ i;
  	}
  
  	/**
  	 * For every i in [0,N), bits[i] is the list of i's bits, in increasing order.
  	 */
  	int [][] bits (int N) {
  		int M = 1 << N;
  		int [][] res = new int [M][];
  		for (int m = 0; m < M; ++m) {
  			res[m] = new int [Integer.bitCount(m)];
  			int t = m;
  			for (int i = 0; i < res[m].length; ++i) {
  				int j = (t & (-t));
  				res[m][i] = Integer.numberOfTrailingZeros(j);
  				t -= j;
  			}
  		}
  		return res;
  	}
  	private static int [] rep (int S, int T) { if (S >= T) return new int [0]; int [] res = new int [T-S]; for (int i = S; i < T; ++i) res[i-S] = i; return res; }
  	//////////////////////////////////////////////////////////////////////////////////// OFF
  	private static IOUtils.MyScanner sc = new IOUtils.MyScanner();
  	private static class IOUtils {
  		public static class MyScanner {
  			public String next () { newLine(); return line[index++]; }
  			public int nextInt () { return Integer.parseInt(next()); }
  			//////////////////////////////////////////////
  			private boolean eol () { return index == line.length; }
  			private String readLine () {
  				try {
  					int b;
  					StringBuilder res = new StringBuilder();
  					while ((b = System.in.read()) < ' ')
  						continue;
  					res.append((char)b);
  					while ((b = System.in.read()) >= ' ')
  						res.append((char)b);
  					return res.toString();
  				} catch (Exception e) {
  					throw new Error (e);
  				}
  			}
  			private MyScanner () {
  				try {
  					while (System.in.available() == 0)
  						Thread.sleep(1);
  					start();
  				} catch (Exception e) {
  					throw new Error(e);
  				}
  			}
  			private String [] line;
  			private int index;
  			private void newLine () {
  				if (line == null || eol()) {
  					line = split(readLine());
  					index = 0;
  				}
  			}
  			private String [] split (String s) { return s.length() > 0 ? s.split(" ") : new String [0]; }
  		}
  		private static String build (Object o, Object ... A) { return buildDelim(" ", o, A); }
  		private static String buildDelim (String delim, Object o, Object ... A) {
  			java.util.List<String> str = new java.util.ArrayList<>();
  			append(str, o);
  			for (Object p : A)
  				append(str, p);
  			return String.join(delim, str.toArray(new String [0]));
  		}
  		//////////////////////////////////////////////////////////////////////////////////
  		private static java.text.DecimalFormat formatter = new java.text.DecimalFormat("#.#########");
  		private static void start () { if (t == 0) t = millis(); }
  		private static void append (java.util.function.Consumer<Object> f, java.util.function.Consumer<Object> g, Object o) {
  			if (o.getClass().isArray()) {
  				int len = java.lang.reflect.Array.getLength(o);
  				for (int i = 0; i < len; ++i)
  					f.accept(java.lang.reflect.Array.get(o, i));
  			}
  			else if (o instanceof Iterable<?>)
  				((Iterable<?>)o).forEach(f::accept);
  			else
  				g.accept(o instanceof Double ? formatter.format(o) : o);
  		}
  		private static void append (java.util.List<String> str, Object o) {
  			append(x -> append(str, x), x -> str.add(x.toString()), o);
  		}
  		private static java.io.PrintWriter pw = new java.io.PrintWriter(System.out);
  		private static void flush () { pw.flush(); System.out.flush(); }
  		private static void print (Object o, Object ... A) {
  			String res = build(o, A);
  			if (DEBUG == 2)
  				err(res, '(', time(), ')');
  			if (res.length() > 0)
  				pw.println(res);
  			if (DEBUG == 1)
  				flush();
  		}
  		private static void err (Object o, Object ... A) { System.err.println(build(o, A)); }
  		private static int DEBUG;
  		private static void exit () {
  			String end = "------------------" + System.lineSeparator() + time();
  			switch(DEBUG) {
  			case 1: print(end); break;
  			case 2: err(end); break;
  			}
  			IOUtils.pw.close();
  			System.out.flush();
  			System.exit(0);
  		}
  		private static long t;
  		private static long millis () { return System.currentTimeMillis(); }
  		private static String time () { return "Time: " + (millis() - t) / 1000.0; }
  		private static void run (int N) {
  			try { DEBUG = Integer.parseInt(System.getProperties().get("DEBUG").toString()); }
  			catch (Throwable t) {}
  
  			for (int n = 1; n <= N; ++n) {
  				Object res = new B().solve();
  				if (res != null) {
  					@SuppressWarnings("all")
  					Object o = CONTEST_TYPE == 0 ? "Case #" + n + ": " + build(res) : res;
  					print(o);
  				}
  			}
  			exit();
  		}
  	}
  	////////////////////////////////////////////////////////////////////////////////////
  	public static void main (String[] args) {
  		@SuppressWarnings("all")
  		int N = CONTEST_TYPE == 1 ? 1 : sc.nextInt();
  		init();
  		IOUtils.run(N);
  	}
  }
  