You are given n integers a_1, a_2, …, a_n and an integer k. Find the maximum value of i ⋅ j - k ⋅ (a_i | a_j) over all pairs (i, j) of integers with 1 ≤ i < j ≤ n. Here, | is the [bitwise OR operator](https://en.wikipedia.org/wiki/Bitwise_operation#OR).

Input

The first line contains a single integer t (1 ≤ t ≤ 10 000) — the number of test cases.

The first line of each test case contains two integers n (2 ≤ n ≤ 10^5) and k (1 ≤ k ≤ min(n, 100)).

The second line of each test case contains n integers a_1, a_2, …, a_n (0 ≤ a_i ≤ n).

It is guaranteed that the sum of n over all test cases doesn't exceed 3 ⋅ 10^5.

Output

For each test case, print a single integer — the maximum possible value of i ⋅ j - k ⋅ (a_i | a_j).

Example

Input


4
3 3
1 1 3
2 2
1 2
4 3
0 1 2 3
6 6
3 2 0 0 5 6


Output


-1
-4
3
12

Note

Let f(i, j) = i ⋅ j - k ⋅ (a_i | a_j).

In the first test case, 

  * f(1, 2) = 1 ⋅ 2 - k ⋅ (a_1 | a_2) = 2 - 3 ⋅ (1 | 1) = -1. 
  * f(1, 3) = 1 ⋅ 3 - k ⋅ (a_1 | a_3) = 3 - 3 ⋅ (1 | 3) = -6. 
  * f(2, 3) = 2 ⋅ 3 - k ⋅ (a_2 | a_3) = 6 - 3 ⋅ (1 | 3) = -3. 



So the maximum is f(1, 2) = -1.

In the fourth test case, the maximum is f(3, 4) = 12.
//package MyPackage;
import java.io.*;
import java.util.*;
public class MyClass {
    final static long mod = 1_000_000_007;
    final static int mini = Integer.MIN_VALUE;
    final static int maxi = Integer.MAX_VALUE;
    static long gcd(long a, long b) {
        if (b == 0) return a;
        return gcd(b, a % b);
    }
    static boolean isPrime(int n) {
        if (n <= 1)
            return false;
        else if (n == 2)
            return true;
        else if (n % 2 == 0)
            return false;
        for (int i = 3; i <= Math.sqrt(n); i += 2) {
            if (n % i == 0)
                return false;
        }
        return true;
    }
    static int digits(long n) {
        int count = 0;
        long temp = n;
        while (temp > 0) {
            temp /= 10;
            count++;
        }
        return count;
    }
    static boolean isPalindrome(long i) {
        long originalNum = i;
        long remainder;
        long reversedNum = 0;
        while (i != 0) {
            remainder = i % 10;
            reversedNum = reversedNum * 10 + remainder;
            i /= 10;
        }
        return originalNum == reversedNum;
    }
    static long lcm(long a, long b) {
        return (a / gcd(a, b)) * b;
    }
    static void sort(long[] a) {
        ArrayList<Long> l = new ArrayList<>();
        for (long value : a) {
            l.add(value);
        }
        Collections.sort(l);
        for (int i = 0; i < l.size(); i++)
            a[i] = l.get(i);
    }
    static void sort(int[] a) {
        ArrayList<Integer> l = new ArrayList<>();
        for (int value : a) {
            l.add(value);
        }
        Collections.sort(l);
        for (int i = 0; i < l.size(); i++)
            a[i] = l.get(i);
    }
    static void reverse(int[] arr) {
        int l = 0;
        int h = arr.length - 1;
        while (l < h) {
            swap(arr, l, h);
            l++;
            h--;
        }
    }
    static String reverse(String s) {
        StringBuilder res = new StringBuilder(s);
        return res.reverse().toString();
    }
    static long fact(long n) {
        long res = 1, i;
        for (i = 2; i <= n; i++)
            res *= i;
        return res;
    }
    static void swap(int[] arr, int i, int j) {
        int temp = arr[i];
        arr[i] = arr[j];
        arr[j] = temp;
    }
    static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        public FastReader() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        String n() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nint() {
            return Integer.parseInt(n());
        }

        float nfloat() {
            return Float.parseFloat(n());
        }

        long nlong() {
            return Long.parseLong(n());
        }

        double ndouble() {
            return Double.parseDouble(n());
        }

        int[] narr(int n) {
            int[] a = new int[n];
            for (int i = 0; i < n; i++) a[i] = nint();
            return a;
        }

        int[][] narr(int n, int m) {
            int[][] a = new int[n][m];
            for (int i = 0; i < n; i++)
                for (int j = 0; j < m; j++)
                    a[i][j] = nint();
            return a;
        }

        String nline() {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
    }
    public static class Pair {
        int a;
        int b;

        public Pair(int a, int b) {
            this.a = a;
            this.b = b;
        }
    }
    public static void main(String[] args) {
        FastReader sc = new FastReader();
        PrintWriter out = new PrintWriter(System.out);
        int t = sc.nint();
        while(t-- > 0) {
            int n = sc.nint();
            int k = sc.nint();
            int[] arr = sc.narr(n);
            int max = mini;
            for(int i = n - 1; i >= Math.max(0, n - 105); i--) {
                for(int j = i - 1; j >= Math.max(0, n - 105); j--) {
                    max = Math.max(max, (i + 1) * (j + 1) - k * (arr[i] | arr[j]));
                }
            }
            out.println(max);
        }
        out.flush();
        out.close();
    }
}