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

public class Main {
    public static void main(String args[]) {new Main().run();}

    FastReader in = new FastReader();
    PrintWriter out = new PrintWriter(System.out);
    void run() {
        for(int q=ni();q>0;q--)
        work();
        out.flush();
    }
    long mod=998244353;
    long gcd(long a,long b) {
        return a==0?b:gcd(b%a,a);
    }
    long inf=Long.MAX_VALUE/3;

    void work() {
        int n=ni(),m=ni();
        int v=0;
        for(int i=30;i>=0;i--){
            if((1<<i&n)==0&&(1<<i&m)>0){
                v+=1<<i;
            }else if((1<<i&n)>0&&(1<<i&m)==0){
                break;
            }
        }
        if((v^n)==m){
            for(int i=0;i<=30;i++){
                if(((1<<i)&m)>0){
                    if(((1<<i)&v)>0){
                        v-=1<<i;
                    }
                }else{
                    v+=1<<i;
                    break;
                }
            }
        }
        out.println(v);
    }

    //input
    @SuppressWarnings("unused")
    private ArrayList<Integer>[] ng(int n, int m) {
        ArrayList<Integer>[] graph=(ArrayList<Integer>[])new ArrayList[n];
        for(int i=0;i<n;i++) {
            graph[i]=new ArrayList<>();
        }
        for(int i=1;i<=m;i++) {
            int s=in.nextInt()-1,e=in.nextInt()-1;
            graph[s].add(e);
            graph[e].add(s);
        }
        return graph;
    }

    private ArrayList<long[]>[] ngw(int n, int m) {
        ArrayList<long[]>[] graph=(ArrayList<long[]>[])new ArrayList[n];
        for(int i=0;i<n;i++) {
            graph[i]=new ArrayList<>();
        }
        for(int i=1;i<=m;i++) {
            long s=in.nextLong()-1,e=in.nextLong()-1,w=in.nextLong();
            graph[(int)s].add(new long[] {e,w});
            graph[(int)e].add(new long[] {s,w});
        }
        return graph;
    }

    private int ni() {
        return in.nextInt();
    }

    private long nl() {
        return in.nextLong();
    }
    private double nd() {
        return in.nextDouble();
    }
    private String ns() {
        return in.next();
    }

    private long[] na(int n) {
        long[] A=new long[n];
        for(int i=0;i<n;i++) {
            A[i]=in.nextLong();
        }
        return A;
    }

    private int[] nia(int n) {
        int[] A=new int[n];
        for(int i=0;i<n;i++) {
            A[i]=in.nextInt();
        }
        return A;
    }
}

class FastReader
{
    BufferedReader br;
    StringTokenizer st;
    InputStreamReader input;//no buffer
    public FastReader()
    {
        br=new BufferedReader(new InputStreamReader(System.in));
    }

    public FastReader(boolean isBuffer)
    {
        if(!isBuffer){
            input=new InputStreamReader(System.in);
        }else{
            br=new BufferedReader(new InputStreamReader(System.in));
        }
    }

    public boolean hasNext(){
        try{
            String s=br.readLine();
            if(s==null){
                return  false;
            }
            st=new StringTokenizer(s);
        }catch(IOException e){
            e.printStackTrace();
        }
        return true;
    }

    public String next()
    {   
        if(input!=null){
            try {
                StringBuilder sb=new StringBuilder();
                int ch=input.read();
                while(ch=='\n'||ch=='\r'||ch==32){
                    ch=input.read();
                }
                while(ch!='\n'&&ch!='\r'&&ch!=32){
                    sb.append((char)ch);
                    ch=input.read();
                }
                return sb.toString();
            }catch (Exception e){
                e.printStackTrace();
            }
        }
        while(st==null || !st.hasMoreElements())//回车，空行情况
        {
            try {
                st = new StringTokenizer(br.readLine());
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return st.nextToken();
    }

    public int nextInt()
    {
        return (int)nextLong();
    }

    public long nextLong() {
        try {
            if(input!=null){
                long ret=0;
                int b=input.read();
                while(b<'0'||b>'9'){
                    b=input.read();
                }
                while(b>='0'&&b<='9'){
                    ret=ret*10+(b-'0');
                    b=input.read();
                }
                return ret;
            }
        }catch (Exception e){
            e.printStackTrace();
        }
        return Long.parseLong(next());
    }

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