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.util.*;import java.io.*;import java.math.*;
public class CF1554B
{
    static boolean memory = true;
    static long mod = 998244353;
    static long MOD = 1000000007; 
    
    static void ruffleSort(int[] a) {
        int n = a.length;
        ArrayList<Integer> lst = new ArrayList<>();
        for(int i : a)
            lst.add(i);
        Collections.sort(lst);
        for(int i = 0; i < n; i++)
            a[i] = lst.get(i);
    }

    static void ruffleSort(long[] a) {
        int n = a.length; 
        ArrayList<Long> lst = new ArrayList<>();
        for(long i : a)
            lst.add(i);
        Collections.sort(lst);
        for(int i = 0; i < n; i++)
            a[i] = lst.get(i);
    }

    public static void process()throws IOException
    {
        int n = ni(), k = ni();
        long[] a = nal(n);
        long max = Integer.MIN_VALUE;;
        for(int i = n-1; i >= Math.max(0, n-300); i--){
            for(int j = i-1; j >= Math.max(0, n-300); j--)
                max = Math.max(max, (i+1)*(long)(j+1) - k*(a[i]|a[j]));
        }
        pn(max);
    }
   
    static AnotherReader sc;
    static PrintWriter out;

    public static void main(String[] args) throws Exception{
        if(memory)new Thread(null, new Runnable() {public void run(){try{new CF1554B().run();}catch(Exception e){e.printStackTrace();System.exit(1);}}}, "1", 1 << 32).start();
        else new CF1554B().run();
    }

    void run()throws Exception
    {
        boolean oj = System.getProperty("ONLINE_JUDGE") != null;
        if(oj){sc=new AnotherReader();out=new PrintWriter(System.out);}
        else{sc=new AnotherReader(100);out=new PrintWriter("output.txt");}
        long s = System.currentTimeMillis();
        int t=1;
        t=ni();
        //int k = t;
        while(t-->0) {/*p("Case #"+ (k-t) + ": ")*/;process();}
        out.flush();
        System.err.println(System.currentTimeMillis()-s+"ms");
        out.close();
    }

    static long power(long k, long c, long mod){
        long y = 1;
        while(c > 0){
            if(c%2 == 1)
                y = y * k % mod;
            c = c/2;
            k = k * k % mod;
        }
        return y;
    }

    static int power(int x, int y, int p){ 
        int res = 1;
        x = x % p;
        while (y > 0) {
            if (y % 2 == 1)
                res = (res * x) % p;
            y = y >> 1;
            x = (x * x) % p;
        }
        return res;
    }

    static int log2(int N)
    {
        int result = (int)(Math.log(N) / Math.log(2));
        return result;
    }

 
    static void pn(Object o){out.println(o);}
    static void pn(int[] a){for(int i : a)out.print(i+" ");pn("");}
    static void pn(long[] a){for(long i : a)out.print(i+" ");pn("");}
    static void p(Object o){out.print(o);}
    static void YES(){out.println("YES");}
    static void NO(){out.println("NO");}
    static void yes(){out.println("yes");}
    static void no(){out.println("no");}
    static void p(int[] a){for(int i : a)out.print(i+" ");}
    static void p(long[] a){for(long i : a)out.print(i+" ");}
    static void pni(Object o){out.println(o);out.flush();}
    static int ni()throws IOException{return sc.nextInt();}
    static long nl()throws IOException{return sc.nextLong();}
    static double nd()throws IOException{return sc.nextDouble();}
    static String nln()throws IOException{return sc.nextLine();}
    static String ns()throws IOException{return sc.next();}
    static int[] nai(int N)throws IOException{int[]A=new int[N];for(int i=0;i!=N;i++){A[i]=ni();}return A;}
    static long[] nal(int N)throws IOException{long[]A=new long[N];for(int i=0;i!=N;i++){A[i]=nl();}return A;}
    static long gcd(long a, long b)throws IOException{return (b==0)?a:gcd(b,a%b);}
    static int gcd(int a, int b)throws IOException{return (b==0)?a:gcd(b,a%b);}
    static int bit(long n)throws IOException{return (n==0)?0:(1+bit(n&(n-1)));}
    
/////////////////////////////////////////////////////////////////////////////////////////////////////////
 
    static class AnotherReader{BufferedReader br; StringTokenizer st;
    AnotherReader()throws FileNotFoundException{
    br=new BufferedReader(new InputStreamReader(System.in));}
    AnotherReader(int a)throws FileNotFoundException{
    br = new BufferedReader(new FileReader("input.txt"));}
    String next()throws IOException{
    while (st == null || !st.hasMoreElements()) {try{
    st = new StringTokenizer(br.readLine());}
    catch (IOException  e){ e.printStackTrace(); }}
    return st.nextToken(); } int nextInt() throws IOException{
    return Integer.parseInt(next());}
    long nextLong() throws IOException
    {return Long.parseLong(next());}
    double nextDouble()throws IOException { return Double.parseDouble(next()); }
    String nextLine() throws IOException{ String str = ""; try{
    str = br.readLine();} catch (IOException e){
    e.printStackTrace();} return str;}}

/////////////////////////////////////////////////////////////////////////////////////////////////////////////
}