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.

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.StringTokenizer;

public class Solver {

    public static void main(String[] args) {
        FastReader in = new FastReader();
        PrintWriter out = new PrintWriter(System.out);
        new TaskA().solveB(in, out);
        out.close();
    }

    static class TaskA {
        public void solveA(FastReader in, PrintWriter out) {
            int t = in.nextInt();

            while (t-- > 0) {
                int n = in.nextInt();
                long[] array = in.nextLongArray(n);
                long result = Long.MIN_VALUE;

                for (int i = 0; i < n - 1; i++) {
                    result = Math.max(result, (array[i] * array[i + 1]));
                }
                out.println(result);
            }
        }

        public void solveB(FastReader in, PrintWriter out) {
            int t = in.nextInt();

            while (t-- > 0) {
                int n = in.nextInt();
                int k = in.nextInt();
                long[] array = in.nextLongArray(n);
                long max = Long.MIN_VALUE;

                int start = Math.max(0, n - 2 * k);

                for (int i = start; i < n - 1; i++) {
                    for (int j = i + 1; j < n; j++) {
                        max = Math.max(max, (((i + 1l) * (j + 1l)) - (k * (array[i] | array[j]))));
                    }
                }
                out.println(max);
            }
        }

        public void solveC(FastReader in, PrintWriter out) {

        }

        public void solveD(FastReader in, PrintWriter out) {

        }

        public void solveE(FastReader in, PrintWriter out) {

        }
    }

    private static long gcd(long a, long b) {
        if (a == 0) {
            return b;
        }
        return gcd(b % a, a);
    }

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

    private static int min(int a, int b) {
        return a < b ? a : b;
    }

    private static int max(int a, int b) {
        return a > b ? a : b;
    }

    private static int min(ArrayList<Integer> list) {
        int min = Integer.MAX_VALUE;
        for (int el : list) {
            if (el < min) {
                min = el;
            }
        }
        return min;
    }

    private static int max(ArrayList<Integer> list) {
        int max = Integer.MIN_VALUE;
        for (int el : list) {
            if (el > max) {
                max = el;
            }
        }
        return max;
    }

    private static int min(int[] list) {
        int min = Integer.MAX_VALUE;
        for (int el : list) {
            if (el < min) {
                min = el;
            }
        }
        return min;
    }

    private static int max(int[] list) {
        int max = Integer.MIN_VALUE;
        for (int el : list) {
            if (el > max) {
                max = el;
            }
        }
        return max;
    }

    private static void fill(int[] array, int value) {
        for (int i = 0; i < array.length; i++) {
            array[i] = value;
        }
    }

    static class FastReader {
        BufferedReader br;
        StringTokenizer st;

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

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

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

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

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

        String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }

        int[] nextIntArray(int n) {
            int[] array = new int[n];
            for (int i = 0; i < n; i++) {
                array[i] = nextInt();
            }
            return array;
        }

        long[] nextLongArray(int n) {
            long[] array = new long[n];
            for (int i = 0; i < n; i++) {
                array[i] = nextLong();
            }
            return array;
        }
    }
}