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.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.StringTokenizer;

public class A {
    private String nextToken() throws IOException {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            tokenizer = new StringTokenizer(reader.readLine());
        }
        return tokenizer.nextToken();
    }

    private int nextInt() throws NumberFormatException, IOException {
        return Integer.parseInt(nextToken());
    }

    private double nextDouble() throws NumberFormatException, IOException {
        return Double.parseDouble(nextToken());
    }

    private long nextLong() throws IOException {
        return Long.parseLong(nextToken());
    }

    private void print(Object o) {
        writer.print(o);
    }

    private void println(Object o) {
        writer.println(o);
    }

    private void printf(String format, Object... o) {
        writer.printf(format, o);
    }

    public static void main(String[] args) {
        long time = System.currentTimeMillis();
        Locale.setDefault(Locale.US);
        new A().run();
        System.err.printf("%.3f\n", 1e-3 * (System.currentTimeMillis() - time));
    }

    BufferedReader reader;
    StringTokenizer tokenizer;
    PrintWriter writer;

    private void run() {
        try {
            reader = new BufferedReader(new InputStreamReader(System.in));
            writer = new PrintWriter(System.out);
            solve();
            reader.close();
            writer.close();
        } catch (IOException e) {
            e.printStackTrace();
            System.exit(13);
        }
    }

    private void solve() throws IOException {
        for (int t = nextInt(); t > 0; t--) {
            int n = nextInt();
            int x = nextInt();
            int[] a = new int[n];
            int[] b = new int[n + 1];

            for (int i = 0; i < n; i++) {
                a[i] = b[i] = nextInt();
            }
            b[n] = x;
            Arrays.sort(b);

            Map<Integer, List<Integer>> map = new HashMap<>();
            for (int i = 0; i <= n; i++) {
                if (!map.containsKey(b[i])) {
                    map.put(b[i], new ArrayList<>());
                }
                map.get(b[i]).add(i);
            }

            int result = 0;
            while (x != b[n]) {
                if (sorted(a)) {
                    break;
                }

                List<Integer> indices = map.get(x);
                int idx = -1;
                for (int i = 0; i < indices.size(); i++) {
                    idx = indices.get(i);
                    if (idx < n && a[idx] > x) {
                        break;
                    }
                }
                if (a[idx] > x) {
                    int tmp = x;
                    x = a[idx];
                    a[idx] = tmp;
                    result++;
                } else {
                    break;
                }
            }

            if (sorted(a)) {
                println(result);
            } else {
                println(-1);
            }

        }
    }

    private boolean sorted(int[] a) {
        for (int i = 1; i < a.length; i++) {
            if (a[i - 1] > a[i]) {
                return false;
            }
        }

        return true;
    }
}
