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.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.StringTokenizer;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 * @author vishu03
*/public class Main {
	public static void main(String[] args) {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		InputReader in = new InputReader(inputStream);
		PrintWriter out = new PrintWriter(outputStream);
		DSequenceAndSwaps solver = new DSequenceAndSwaps();
		solver.solve(1, in, out);
		out.close();
	}
static class DSequenceAndSwaps   {
public void solve(int testNumber, InputReader in, PrintWriter out) {
        int t;
        t = in.nextInt();
        //t = 1;
        while (t > 0) {

            t--;

            int n, x, a = 0, b = 0, c, d = 0;
            n = in.nextInt();
            x = in.nextInt();
            int[] arr = new int[n];

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

            for (int i = 0; i < n - 1; i++) {
                if (arr[i] > arr[i + 1]) {
                    a++;
                    d = i;
                }
            }
            if (a == 0) {
                out.println(0);
            } else {
                a = 0;
                for (int i = 0; i < n; i++) {
                    if (i == d + 1) {
                        break;
                    }
                    if (arr[i] > x) {
                        c = arr[i];
                        arr[i] = x;
                        x = c;
                        a++;
                    }

                }

                for (int i = 0; i < n - 1; i++) {
                    if (arr[i] > arr[i + 1]) {
                        b++;
                        break;
                    }
                }
                if (b == 0) {
                    out.println(a);
                } else
                    out.println(-1);
            }


        }
    }

}
static class InputReader   {
public BufferedReader reader;
public StringTokenizer tokenizer;

public InputReader(InputStream stream) {
        reader = new BufferedReader(new InputStreamReader(stream), 32768);
        tokenizer = null;
    }

public String next() {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken();
    }

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

}
}

