You are given a sequence a consisting of n integers a_1, a_2, ..., a_n, and an integer x. Your task is to make the sequence a sorted (it is considered sorted if the condition a_1 ≤ a_2 ≤ a_3 ≤ ... ≤ a_n holds).

To make the sequence sorted, you may perform the following operation any number of times you want (possibly zero): choose an integer i such that 1 ≤ i ≤ n and a_i > x, and swap the values of a_i and x.

For example, if a = [0, 2, 3, 5, 4], x = 1, the following sequence of operations is possible:

  1. choose i = 2 (it is possible since a_2 > x), then a = [0, 1, 3, 5, 4], x = 2; 
  2. choose i = 3 (it is possible since a_3 > x), then a = [0, 1, 2, 5, 4], x = 3; 
  3. choose i = 4 (it is possible since a_4 > x), then a = [0, 1, 2, 3, 4], x = 5. 



Calculate the minimum number of operations you have to perform so that a becomes sorted, or report that it is impossible.

Input

The first line contains one integer t (1 ≤ t ≤ 500) — the number of test cases.

Each test case consists of two lines. The first line contains two integers n and x (1 ≤ n ≤ 500, 0 ≤ x ≤ 500) — the number of elements in the sequence and the initial value of x.

The second line contains n integers a_1, a_2, ..., a_n (0 ≤ a_i ≤ 500).

The sum of values of n over all test cases in the input does not exceed 500.

Output

For each test case, print one integer — the minimum number of operations you have to perform to make a sorted, or -1, if it is impossible.

Example

Input


6
4 1
2 3 5 4
5 6
1 1 3 4 4
1 10
2
2 10
11 9
2 10
12 11
5 18
81 324 218 413 324


Output


3
0
0
-1
1
3
import java.util.*;
import java.lang.*;
import java.io.*;

 public class CF{

   // static int MOD=1e9+7;

     public static void main (String[] args) 
    {
 
            FastReader scan = new FastReader();
            PrintWriter out = new PrintWriter(System.out);
            Task solver = new Task();
            int testcase = scan.nextInt();
                
           //int testcase = 1;
            for(int tt = 1; tt <= testcase ; tt++) solver.solve(tt, scan, out);
            out.close();
        
    }


     static boolean isSorted(int[] arr ,int n){

        boolean flag = true;

        if(n ==1){
            return flag;
        }else{


        for(int i =1 ;i<n;i++){

            if(arr[i] < arr[i-1]){

                flag = false;
                break;
            }
            

        }


    }

    return flag;
    }

    
    // main code in task 
    
      static class Task {
     
            public void solve(int testNumber, FastReader scan, PrintWriter out) {

            int n =scan.nextInt();
            int x = scan.nextInt();
              int count = 0 ;
            int[] arr = new int[n];

            for(int i=0;i<n;i++) arr[i] = scan.nextInt();

            if(isSorted(arr,n)){
                out.println("0");
            }else{

                    // if(n==1) out.println("0");
                    // else{
               

                    loop: for(int i = 0; i< n;i++)
                {
                           if(arr[i] > x){
 
                            count++;
                             
                            int d = x ;
                            x = arr[i]; arr[i] = d;

                            if(isSorted(arr,n)){
                                out.println(count);
                                return ;
                            }

 
                         }
 
              //  }
            }


            out.println("-1");
               // if(isSorted(arr,n) == false)  out.println("-1")  ;
               //     else{
               //          out.println(count);
               //    }


            } 

        }
 
    }
        
 
 static class FastReader {
            BufferedReader br;
            StringTokenizer st;
     
            public FastReader() {
                br = new BufferedReader(new InputStreamReader(System.in));
            }
     
            public FastReader(String s) throws FileNotFoundException {
                br = new BufferedReader(new FileReader(new File(s)));
            }
     
            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;
            }
            
       

 
 
        }


 }       