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.BufferedInputStream;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Scanner;
import java.util.StringTokenizer;

public class Main {
	public static void main(String[] args) throws Exception {
		new Main();
	}
	
	InputReader ir;
	public Main()  throws Exception {
		ir = new InputReader(System.in);
		int tc = ir.nextInt();
		while(tc-->0)
		solve();
	}
	
	private boolean checkSorted(int[] a, int n) {
		for(int i=1; i<n; i++) {
			if(a[i] < a[i-1]) {
				return false;
			}
		}
		return true;
	}
	
	private void solve() {
		int n = ir.nextInt();
		int x = ir.nextInt();
		int[] a = new int[n];
		for(int i=0; i<n; i++) a[i] = ir.nextInt();
		if(!checkSorted(a, n)) {
			int ans = 0;
			for(int i=0; i<n; i++) {
				if(a[i] > x) {
					int tmp = a[i];
					a[i] = x;
					x = tmp;
					ans ++;
					if(checkSorted(a, n)) {
						System.out.println(ans);
						return;
					}
				}
			}
			System.out.println(-1);
			
		} else System.out.println(0);
	}
	
	
	class InputReader {
		private BufferedReader reader;
		private StringTokenizer tokenizer;
		
		public InputReader(InputStream is) {
			reader = new BufferedReader(new InputStreamReader(is), 8*2014);
			tokenizer = null;
		}
		
		public String next() {
			while(tokenizer == null || !tokenizer.hasMoreElements()) {
				try {
					tokenizer = new StringTokenizer(reader.readLine());
				} catch (IOException e) {
					throw new RuntimeException();
				}
			}
			return tokenizer.nextToken();
		}
		
		public Integer nextInt() {
			return Integer.parseInt(next());
		}
	}
}
