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.
// Piyush Nagpal
import java.util.*;
import java.io.*;
 public class C{
     
    static int MOD=1000000007;
    static PrintWriter pw;
    static FastReader sc;
    
    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());}
        
        public char nextChar() throws IOException {return next().charAt(0);}
 
        String nextLine(){
            String str = "";
            try {
                str = br.readLine();
            }
            catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
        public int[] intArr(int n) throws IOException {int[]in=new int[n];for(int i=0;i<n;i++)in[i]=nextInt();return in;}
        public long[] longArr(int n) throws IOException {long[]in=new long[n];for(int i=0;i<n;i++)in[i]=nextLong();return in;}
        
    }   


     public static long gcd(long a,long b){if( b>a ){return gcd(b,a);}if( b==0 ){return a;} return gcd(b,a%b);}
     public static long expo( long a,long b,long M ){long result=1;while(b>0){if( b%2==1 ){result=(result*a)%M;}a=(a*a)%M;b=b/2;}return result%M;}
    public static ArrayList<Long> Sieve(int n){boolean [] arr= new boolean[n+1];Arrays.fill(arr, true);ArrayList<Long> list= new ArrayList<>();for(int i=2;i<=n;i++){if( arr[i]==true ){list.add((long)i);}for(int j=2*i;j<=n;j+=i){arr[j]=false;}}return list;}

    public static void printarr(int [] arr){for(int i=0;i<arr.length;i++){pw.print(arr[i]+" ");}}
    public static void printarr(long [] arr){for(int i=0;i<arr.length;i++){pw.print(arr[i]+" ");}}
    
    // int [] arr=sc.intArr(n);
    static void solve() throws Exception{
    	int n=sc.nextInt(),k=sc.nextInt();
        ArrayList<Integer> list= new ArrayList<>();
        ArrayList<Integer> copy= new ArrayList<>();
        
        for(int i=0;i<n;i++){
            list.add(sc.nextInt());
            copy.add(list.get(i));
        }

        Collections.sort(copy);

        long ans1= (n*(n-1))-((list.get(n-2)|list.get(n-1))*k);

        int min1=(int)(copy.get(0));
        int min2=(int)(copy.get(1));
        int x=0,y=0;
        for(int i=0;i<n;i++){
        	if(list.get(i)==min1){
        		x=i;
        		break;
        	}
        }
        
        for(int i=x+1;i<n;i++){
        	if(list.get(i)==min2){
        		y=i;
        		break;
        	}
        }
        x++; y++;
        long ans2= (x*y)-(k*(min1|min2));

        pw.println(Math.max(ans1,ans2));


        
 }
    
   public static void main(String[] args) throws Exception{
        try {
            System.setIn(new FileInputStream("input.txt"));
            System.setOut(new PrintStream(new FileOutputStream("output.txt")));
        } catch (Exception e) {
            System.err.println("Error");
        }
        sc= new FastReader();
        pw = new PrintWriter(System.out);

   
        int tc=1;
        tc=sc.nextInt();
        for(int i=1;i<=tc;i++) {
//            pw.printf("Case #%d: "b, i);
            solve();
        }
       
        pw.flush();

    

    }

}