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.
//package codeforces.problemset.score.s_1800.P_1554_C;

import java.io.*;
import java.util.StringTokenizer;

/**
 * https://codeforces.com/problemset/problem/1554/C
 * C. Mikasa
 * */
public class Main {
    public static void main(String[] args) throws FileNotFoundException {
        FastScan sc = new FastScan(System.in);
        //FastScan sc = new FastScan("E:\\3.study\\2.git_workspace\\algorithm_topic\\src\\main\\java\\codeforces\\problemset\\score\\s_1600\\P_1539_D\\input_01.txt");
        //FastScan sc = new FastScan("E:\\3.study\\2.git_workspace\\algorithm\\src\\main\\java\\codeforces\\problemset\\segment_tree\\div2_1187_D\\input_01.txt");
        PrintWriter out = new PrintWriter(System.out);

        int t = sc.nextInt();
        while(t-- > 0){
            int n = sc.nextInt(), m = sc.nextInt();
            m++;
            int ans = 0;
            for(int i = 30; i >= 0 && n < m; i--){
                if(((n >> i) & 1) == ((m >> i) & 1)){
                    continue;
                }

                if(((n >> i) & 1) == 0 && ((m >> i) & 1) == 1){
                    ans |= (1 << i);
                    n |= (1 << i);
                }
            }
            out.println(ans);
        }

        out.flush();
        out.close();
    }

    static class FastScan {
        StringTokenizer st;
        BufferedReader br;

        public FastScan(InputStream s) {
            br = new BufferedReader(new InputStreamReader(s));
        }

        public FastScan(String debugInputFileName) throws FileNotFoundException {
            br = new BufferedReader(new FileReader(debugInputFileName));
        }

        public String next() {
            while (st == null || !st.hasMoreTokens()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (Exception e) {
                }
            }
            return st.nextToken();
        }

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

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