You are given two integers n and m. Find the \operatorname{MEX} of the sequence n ⊕ 0, n ⊕ 1, …, n ⊕ m. Here, ⊕ is the [bitwise XOR operator](https://en.wikipedia.org/wiki/Bitwise_operation#XOR).

\operatorname{MEX} of the sequence of non-negative integers is the smallest non-negative integer that doesn't appear in this sequence. For example, \operatorname{MEX}(0, 1, 2, 4) = 3, and \operatorname{MEX}(1, 2021) = 0. 

Input

The first line contains a single integer t (1 ≤ t ≤ 30 000) — the number of test cases.

The first and only line of each test case contains two integers n and m (0 ≤ n, m ≤ 10^9).

Output

For each test case, print a single integer — the answer to the problem.

Example

Input


5
3 5
4 6
3 2
69 696
123456 654321


Output


4
3
0
640
530866

Note

In the first test case, the sequence is 3 ⊕ 0, 3 ⊕ 1, 3 ⊕ 2, 3 ⊕ 3, 3 ⊕ 4, 3 ⊕ 5, or 3, 2, 1, 0, 7, 6. The smallest non-negative integer which isn't present in the sequence i. e. the \operatorname{MEX} of the sequence is 4.

In the second test case, the sequence is 4 ⊕ 0, 4 ⊕ 1, 4 ⊕ 2, 4 ⊕ 3, 4 ⊕ 4, 4 ⊕ 5, 4 ⊕ 6, or 4, 5, 6, 7, 0, 1, 2. The smallest non-negative integer which isn't present in the sequence i. e. the \operatorname{MEX} of the sequence is 3.

In the third test case, the sequence is 3 ⊕ 0, 3 ⊕ 1, 3 ⊕ 2, or 3, 2, 1. The smallest non-negative integer which isn't present in the sequence i. e. the \operatorname{MEX} of the sequence is 0.
import java.io.*;
import java.math.BigInteger;
import java.util.*;
import static java.lang.Math.*;

public class SolutionC {
    private static FastScanner in = new FastScanner();
    private static PrintWriter out =
        new PrintWriter(new BufferedOutputStream(System.out));

    public static void main(String[] args) {
        
        tests();
        // solve();
        
        out.close();
    }

    static void solve() {
        int n = in.nextInt();
        int m = in.nextInt();
        ++m;

        int answer = 0;
        for (int i = 30; i >= 0 && n < m; i--) {
            if ((n >> i & 1) == (m >> i & 1)) {
                continue;
            }
            else if ((n >> i & 1) == 1 && (m >> i & 1) == 0) {
                break;
            }
            else if ((n >> i & 1) == 0 && (m >> i & 1) == 1) {
                answer |= 1 << i;
            }
        }

        out.println(answer);
        
    }

    static void tests() {
        int t = in.nextInt();
        while (t-- > 0) {
            solve();
        }
    }

    private static class FastScanner {
        private BufferedReader br;
        private StringTokenizer st;
    
        public FastScanner() {
            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;
        }
    }
}
