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.io.*;

public class Main {
    static Scanner sc = new Scanner(System.in);
    static PrintWriter out = new PrintWriter(System.out);
    static BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
    //    long mod = 998244353;
    long mod = (long)1e9+7;
    long[] fac;
    List<Integer>[] tree;

    long sum = 0;
    public static void main(String[] args) throws Exception {
        Main main = new Main();
        int t = sc.nextInt();
//        int t= 1;
        while(t-->0){
//            out.println(main.solve());
            main.solve();
        }
        out.flush();
    }

    void solve() throws Exception {
        int inf = Integer.MAX_VALUE/100;
        int n = neInt(), x = neInt();
        int maxi = x;
        int[] a = new int[n];
        for(int i=0; i<n; i++) {
            a[i] = neInt();
            maxi = Math.max(maxi, a[i]);
        }
        int[][][] dp = new int[n][maxi+1][maxi+1];
        for(int[][] d2:dp){
            for(int[] arr:d2) Arrays.fill(arr, inf);
        }
        int[][] rec = new int[maxi+1][maxi+1];
        dp[0][a[0]][x] = 0;
        if(a[0]>x) dp[0][x][a[0]] = 1;
        for(int to=0; to<=maxi; to++){
            rec[0][to] = dp[0][0][to];
            for(int j=1; j<=maxi; j++){
                rec[j][to] = Math.min(dp[0][j][to], rec[j-1][to]);
            }
        }
        for(int i=1; i<n; i++){
            for(int j=0; j<=a[i]; j++){
                // long temp = inf;
                if(j!=a[i]){
                    for(int k=0; k<=j; k++){
                        dp[i][j][a[i]] = Math.min(dp[i][j][a[i]], dp[i-1][k][j]+1);
                    }
                } else{
                    // j = a[i];
                    for(int to=0; to<=maxi; to++){
                        dp[i][j][to] = Math.min(dp[i][j][to], rec[j][to]);
                    }
                }
            }
            for(int to=0; to<=maxi; to++){
                rec[0][to] =  dp[i][0][to];
                for(int j=1; j<=maxi; j++){
                    rec[j][to] = Math.min(dp[i][j][to], rec[j-1][to]);
                }
            }
        }
        int ans = inf;
        for(int j=0; j<=maxi; j++){
            for(int to=0; to<=maxi; to++){
                ans = Math.min(ans, dp[n-1][j][to]);
            }
        }
        if(ans >= inf) ans = -1;
        out.println(ans);

    }
    String neS(){
        return sc.next();
    }
    int neInt(){
        return Integer.parseInt(sc.next());
    }
    long neLong(){
        return Long.parseLong(sc.next());
    }

    int paIn(String s){return Integer.parseInt(s);}

}