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.
//Utilities
import java.io.*;
import java.util.*;

public class B {
	static int t;
	static int n, m;
	
	public static void main(String[] args) throws IOException {
		t = in.iscan();
		while (t-- > 0) {
			run();
		}
		out.close();
	} 
	
	static void run() throws IOException {
		n = in.iscan(); m = in.iscan();
		if (m < n) {
			out.println(0);
			return;
		}
		// m >= n
		int p = 0;
		ArrayList<Integer> pos = new ArrayList<Integer>();
		ArrayList<Integer> add = new ArrayList<Integer>();
		while ((1L << p) <= n) {
			if ((n & (1L << p)) == 0) {
				pos.add(p);
			}
			else {
				add.add(p);
			}
			p++;
		}
		int tmp = 0;
		for (int xx : add) {
			tmp |= 1 << xx;
		}
		while (p < 31) {
			pos.add(p);
			p++;
		}
		int mx = 1 << pos.size();
		int l = 0, r = mx-1, mid, other, cur, res = -1;
		while (l <= r) {
			mid = (l+r)/2;
			other = 0;
			for (int i = 0; i < pos.size(); i++) {
				if ((mid & (1 << i)) > 0) {
					other |= 1 << pos.get(i);
				}
			}
			cur = tmp | other;
			if (cur > m) {
				res = other;
				r = mid-1;
			}
			else {
				l = mid+1;
			}
		}
		out.println(res);
	}

	static INPUT in = new INPUT(System.in);
	static PrintWriter out = new PrintWriter(System.out);
	private static class INPUT {

		private InputStream stream;
		private byte[] buf = new byte[1024];
		private int curChar, numChars;

		public INPUT (InputStream stream) {
			this.stream = stream;
		}

		public INPUT (String file) throws IOException {
			this.stream = new FileInputStream (file);
		}

		public int cscan () throws IOException {
			if (curChar >= numChars) {
				curChar = 0;
				numChars = stream.read (buf);
			}
			
			if (numChars == -1)
				return numChars;

			return buf[curChar++];
		}

		public int iscan () throws IOException {
			int c = cscan (), sgn = 1;
			
			while (space (c))
				c = cscan ();

			if (c == '-') {
				sgn = -1;
				c = cscan ();
			}

			int res = 0;

			do {
				res = (res << 1) + (res << 3);
				res += c - '0';
				c = cscan ();
			}
			while (!space (c));

			return res * sgn;
		}

		public String sscan () throws IOException {
			int c = cscan ();
			
			while (space (c))
				c = cscan ();

			StringBuilder res = new StringBuilder ();

			do {
				res.appendCodePoint (c);
				c = cscan ();
			}
			while (!space (c));

			return res.toString ();
		}

		public double dscan () throws IOException {
			int c = cscan (), sgn = 1;
			
			while (space (c))
				c = cscan ();

			if (c == '-') {
				sgn = -1;
				c = cscan ();
			}

			double res = 0;

			while (!space (c) && c != '.') {
				if (c == 'e' || c == 'E')
					return res * UTILITIES.fast_pow (10, iscan ());
				
				res *= 10;
				res += c - '0';
				c = cscan ();
			}

			if (c == '.') {
				c = cscan ();
				double m = 1;

				while (!space (c)) {
					if (c == 'e' || c == 'E')
						return res * UTILITIES.fast_pow (10, iscan ());

					m /= 10;
					res += (c - '0') * m;
					c = cscan ();
				}
			}

			return res * sgn;
		}

		public long lscan () throws IOException {
			int c = cscan (), sgn = 1;
			
			while (space (c))
				c = cscan ();

			if (c == '-') {
				sgn = -1;
				c = cscan ();
			}

			long res = 0;

			do {
				res = (res << 1) + (res << 3);
				res += c - '0';
				c = cscan ();
			}
			while (!space (c));

			return res * sgn;
		}

		public boolean space (int c) {
			return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
		}
	}

	public static class UTILITIES {

		static final double EPS = 10e-6;
		
		public static void sort(int[] a, boolean increasing) {
			ArrayList<Integer> arr = new ArrayList<Integer>();
			int n = a.length;
			for (int i = 0; i < n; i++) {
				arr.add(a[i]);
			}
			Collections.sort(arr);
			for (int i = 0; i < n; i++) {
				if (increasing) {
					a[i] = arr.get(i);
				}
				else {
					a[i] = arr.get(n-1-i);
				}
			}
		}
		
		public static void sort(long[] a, boolean increasing) {
			ArrayList<Long> arr = new ArrayList<Long>();
			int n = a.length;
			for (int i = 0; i < n; i++) {
				arr.add(a[i]);
			}
			Collections.sort(arr);
			for (int i = 0; i < n; i++) {
				if (increasing) {
					a[i] = arr.get(i);
				}
				else {
					a[i] = arr.get(n-1-i);
				}
			}
		}
		
		public static void sort(double[] a, boolean increasing) {
			ArrayList<Double> arr = new ArrayList<Double>();
			int n = a.length;
			for (int i = 0; i < n; i++) {
				arr.add(a[i]);
			}
			Collections.sort(arr);
			for (int i = 0; i < n; i++) {
				if (increasing) {
					a[i] = arr.get(i);
				}
				else {
					a[i] = arr.get(n-1-i);
				}
			}
		}

		public static int lower_bound (int[] arr, int x) {
			int low = 0, high = arr.length, mid = -1;

			while (low < high) {
				mid = (low + high) / 2;

				if (arr[mid] >= x)
					high = mid;
				else
					low = mid + 1;
			}

			return low;
		}

		public static int upper_bound (int[] arr, int x) {
			int low = 0, high = arr.length, mid = -1;

			while (low < high) {
				mid = (low + high) / 2;

				if (arr[mid] > x)
					high = mid;
				else
					low = mid + 1;
			}

			return low;
		}

		public static long gcd (long a, long b) {
			return b == 0 ? a : gcd (b, a % b);
		}

		public static long lcm (long a, long b) {
			return a * b / gcd (a, b);
		}

		public static long fast_pow_mod (long b, long x, int mod) {
			if (x == 0) return 1;
			if (x == 1) return b;
			if (x % 2 == 0) return fast_pow_mod (b * b % mod, x / 2, mod) % mod;

			return b * fast_pow_mod (b * b % mod, x / 2, mod) % mod;
		}

		public static int fast_pow (int b, int x) {
			if (x == 0) return 1;
			if (x == 1) return b;
			if (x % 2 == 0) return fast_pow (b * b, x / 2);

			return b * fast_pow (b * b, x / 2);
		}

		public static long choose (long n, long k) {
			k = Math.min (k, n - k);
			long val = 1;

			for (int i = 0; i < k; ++i)
				val = val * (n - i) / (i + 1);

			return val;
		}

		public static long permute (int n, int k) {
			if (n < k) return 0;
			long val = 1;

			for (int i = 0; i < k; ++i)
				val = (val * (n - i));

			return val;
		}
		
		// start of permutation and lower/upper bound template
		public static void nextPermutation(int[] nums) {
		    //find first decreasing digit
		    int mark = -1;
		    for (int i = nums.length - 1; i > 0; i--) {
		        if (nums[i] > nums[i - 1]) {
		            mark = i - 1;
		            break;
		        }
		    }
		 
		    if (mark == -1) {
		        reverse(nums, 0, nums.length - 1);
		        return;
		    }
		 
		    int idx = nums.length-1;
		    for (int i = nums.length-1; i >= mark+1; i--) {
		        if (nums[i] > nums[mark]) {
		            idx = i;
		            break;
		        }
		    }
		 
		    swap(nums, mark, idx);
		 
		    reverse(nums, mark + 1, nums.length - 1);
		}
		 
		public static void swap(int[] nums, int i, int j) {
		    int t = nums[i];
		    nums[i] = nums[j];
		    nums[j] = t;
		}
		 
		public static void reverse(int[] nums, int i, int j) {
		    while (i < j) {
		        swap(nums, i, j);
		        i++;
		        j--;
		    }
		}
		
		static int lower_bound (int[] arr, int hi, int cmp) {
			int low = 0, high = hi, mid = -1;
			while (low < high) {
				mid = (low + high) / 2;
				if (arr[mid] >= cmp) high = mid;
				else low = mid + 1;
			}
			return low;
		}
	 
		static int upper_bound (int[] arr, int hi, int cmp) {
			int low = 0, high = hi, mid = -1;
			while (low < high) {
				mid = (low + high) / 2;
				if (arr[mid] > cmp) high = mid;
				else low = mid + 1;
			}
			return low;
		}
		// end of permutation and lower/upper bound template
	}
}
