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.*;
import java.util.*;

public class Main {

    static final int MAX_N = 1000010;
    static final int INF = 0x3f3f3f3f;
    static final int mod = 1000000007;


    public static void main(String[] args) throws IOException {
        initReader(System.in);


        int T = nextInt();
        for (int i = 1; i <= T; i++)
        solve();


        pw.flush();
    }


    /*******************************************************************************************************************************/

    public static void solve() throws IOException {
        long n = nextLong();
        long m = nextLong();

        long ans = Long.MAX_VALUE;
        for (int i = 30; i >= 0; i--) {
            long re1 = (n >> i) << i;
            long re2 = ((m >> i) + 1) << i;
            ans = Math.min(ans, re1 ^ re2);
        }

        pw.println(ans);
    }


    /*******************************************************************************************************************************/

    static class Trie {
        int[][] ch;
        int[] value;
        int size;

        Trie (int maxSize) {
            ch = new int[maxSize * 32][2];
            value = new int[maxSize * 32];
            size = 1;
        }

        public void insert(int x, int inx) {
            int p = 0;
            for (int i = 30; i >= 0; i--) {
                int c = x >> i & 1;
                if (ch[p][c] == 0) ch[p][c] = size++;
                p = ch[p][c];
            }
            value[p] = inx;
        }

        public int query(int x) {
            int p = 0;
            for (int i = 30; i >= 0; i--) {
               int c = x >> i & 1;
               if (ch[p][0] == 0) p = ch[p][1];
               else p = ch[p][0];
            }
            return value[p];
        }
    }

    /*******************************************************************************************************************************/

    static BufferedReader reader;
    static StringTokenizer tokenizer;
    static PrintWriter pw;

    public static void initReader(InputStream input) throws IOException {
        reader = new BufferedReader(new InputStreamReader(input));
        tokenizer = new StringTokenizer("");
        pw = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));

//        reader = new BufferedReader(new FileReader("test.in"));
//        tokenizer = new StringTokenizer("");
//        pw = new PrintWriter(new BufferedWriter(new FileWriter("test1.out")));
    }

    public static boolean hasNext() {
        try {
            while (!tokenizer.hasMoreTokens()) {
                tokenizer = new StringTokenizer(reader.readLine());
            }
        } catch (Exception e) {
            return false;
        }
        return true;
    }

    public static String next() throws IOException {
        while (!tokenizer.hasMoreTokens()) {
            tokenizer = new StringTokenizer(reader.readLine());
        }
        return tokenizer.nextToken();
    }

    public static String nextLine() {
        try {
            return reader.readLine();
        } catch (Exception e) {
            return null;
        }
    }

    public static int nextInt() throws IOException {
        return Integer.parseInt(next());
    }

    public static long nextLong() throws IOException {
        return Long.parseLong(next());
    }

    public static double nextDouble() throws IOException {
        return Double.parseDouble(next());
    }

    public static char nextChar() throws IOException {
        return next().charAt(0);
    }

    public static short nextShort() throws IOException {
        return Short.parseShort(next());
    }

}

