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.util.*;
public class Main {

	public static final int mod=1000000007;	
	static long[][] dp;
	static Map<Integer,Integer> mp;
	static Set<Integer> set;
	public static void main(String[] args) throws IOException {
		
		//File filein = new File("input.txt");
		//BufferedReader sc=new BufferedReader(new FileReader(filein));
		//PrintWriter out=new PrintWriter(new FileWriter("output.txt"));		

		//Scanner sc=new Scanner(System.in);
		BufferedReader sc=new BufferedReader(new InputStreamReader(System.in));
		PrintWriter out=new PrintWriter(System.out);
		int tt=Integer.parseInt(sc.readLine());
		int t=tt;
		mp=new HashMap<>();
		set=new HashSet<>();
		while(t-->0){
			out.flush();
			String[] ip=sc.readLine().split(" ");
			int n=Integer.parseInt(ip[0]);
			int x=Integer.parseInt(ip[1]);
			int[] arr=new int[n];
			ip=sc.readLine().split(" ");
			for(int i=0;i<n;i++){
				arr[i]=Integer.parseInt(ip[i]);
			}
			if(isSorted(arr, 0, n-1)){
				out.println(0);
				continue;
			}
			int cnt=0;
			int temp;
			for(int i=0;i<n;i++){
				if(arr[i]>x){
					temp=arr[i];
					arr[i]=x;
					x=temp;
					cnt++;
					if(isSorted(arr, i+1, n-1)){
						break;
					}
				}
			}

			if(isSorted(arr, 0, n-1))	out.println(cnt);
			else out.println(-1);

		}
		out.flush();
		out.close();
		sc.close();
	}

	static boolean isSorted(int arr[],int i,int j){
		boolean sorted=true;
		while(i<j){
			if(arr[i]>arr[i+1]){
				sorted=false;
				break;
			}
			i++;
		}
		return sorted;
	}


}