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.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.StringTokenizer;

public class SequenceandSwaps {
	
	public static boolean eql(int a[], int b[]) {
		for(int i = 0 ; i < a.length ;i++) {
			if(a[i]!=b[i])return false;
		}
		return true;
	}

	public static void main(String[] args) {
		FastScanner sc =new FastScanner(System.in);
		int t =sc.nextInt();
		for(;t>0;t--) {
			int n =sc.nextInt();
			int x = sc.nextInt();
			int a[]=new int [n];
			int b[]=new int [n];
			for(int i = 0 ; i<n;i++) {
				a[i]=sc.nextInt();b[i]=a[i];
			}
			Arrays.sort(b);
			int c = 0;
			boolean f2 = true;
			while(!eql(a,b)&&f2) {
				//System.out.println(a.equals(b));
				//System.out.println(Arrays.toString(a));
				//System.out.println(Arrays.toString(b));
				boolean f =false;
				int pos = 0;
				for(int i = 0 ; i <n &&!f;i++){
					if(a[i]>x) {
						int temp =x;
						x=a[i];
						a[i]=temp;
						f=true;
						b=a.clone();
						Arrays.sort(b);
						c++;
					}
				}
				f2=f;
			}
			
			//System.out.println(Arrays.toString(a));
			//System.out.println(Arrays.toString(b));
			if(eql(a,b))System.out.println(c);
			else System.out.println(-1);
		}

	}
	
	static class FastScanner {
        BufferedReader br;
        StringTokenizer st;

        FastScanner(InputStream stream) {
            try {
                br = new BufferedReader(new InputStreamReader(stream));
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        String next() {
            while (st == null || !st.hasMoreTokens()) {
                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());
        }
    }

}
