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.*;
import java.lang.reflect.Array;
import java.util.*;
import java.util.stream.Collectors;

public class Main {

    static FastScanner sc;
    static PrintWriter pw;
    static final int INF = 1000000000;

    /*public static Integer cycle_end, cycle_st;
    public static int[] p;
    public static int[] cl;
    public static List<List<Integer>> g;
    public static boolean[] marked;

    static boolean dfs(int v ) {
        cl[v] = 1;
        for(int i = 0; i < g.get(v).size(); ++i) {
            int to = g.get(v).get(i);
            if(cl[to] == 0) {
                p[to] = v;
                if(dfs(to)) return true;
            } else if(cl[to] == 1 && p[v] != to){
                cycle_end = v;
                cycle_st = to;
                return true;
            }
        }

        cl[v] = 2;
        return false;
    }

    static int dfs2(int v, Set<Integer> cycle) {
        marked[v] = true;
        int count = 0;
        for(int i = 0; i < g.get(v).size(); ++i) {
            int to = g.get(v).get(i);
            if(!cycle.contains(to) && !marked[to]) {
                count += dfs2(to, cycle);
            }
        }

        return count + 1;
    }*/

    public static void main(String[] args) throws IOException {
        sc = new FastScanner(System.in);
        pw = new PrintWriter(System.out);

        int ff = sc.nextInt();
        for(int tt = 0; tt < ff; ++tt) {
            int n = sc.nextInt(), x = sc.nextInt();
            int[] a = new int[n];
            for(int i = 0; i < n; ++i)
                a[i] = sc.nextInt();

            int[][][] dp = new int[n][501][501];
            for(int i = 0; i < n; ++i)
                for(int j = 0; j < 501; ++j)
                Arrays.fill(dp[i][j], INF);

            if(a[0] > x)
                dp[0][a[0]][x] = 1;
            
            dp[0][x][a[0]] = 0;

            for(int i = 1; i < n; ++i) {
                for(int sw = 0; sw < 501; ++sw)
                    for(int last = 0; last < 501; ++last) {
                        if(dp[i - 1][sw][last] == INF) continue;

                        if(a[i] >= last)
                            dp[i][sw][a[i]] = Math.min(dp[i][sw][a[i]], dp[i - 1][sw][last]);

                        if(a[i] > sw && sw >= last)
                            dp[i][a[i]][sw] = Math.min(dp[i][a[i]][sw], dp[i - 1][sw][last] + 1);

                    }
            }

            int ans = INF;
            for(int sw = 0; sw < 501; ++sw)
                for(int last = 0; last < 501; ++last)
                    if(dp[n - 1][sw][last] != INF && dp[n - 1][sw][last] < ans)
                        ans = Math.min(ans, dp[n - 1][sw][last]);

            if(ans == INF) pw.println(-1);
            else pw.println(ans);

        }
        pw.close();

    }
}

class FastScanner {
    static StringTokenizer st = new StringTokenizer("");
    static BufferedReader br;

    public FastScanner(InputStream inputStream) {
        br = new BufferedReader(new InputStreamReader(inputStream));
    }

    public String next() throws IOException {
        while (!st.hasMoreTokens())
            st = new StringTokenizer(br.readLine());
        return st.nextToken();
    }

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

    public long nextLong() throws IOException {
        return Long.parseLong(next());
    }
}