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.lang.*;
import java.io.*;

public class First {

	public static void main(String[] args) throws Exception {

//			BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
//			int t = Integer.parseInt(br.readLine());
//			StringBuilder sb = new StringBuilder();
//			while (t-- > 0) {
//				int n = Integer.parseInt(br.readLine());
//				String[] str = (br.readLine()).trim().split(" ");
//				int[] arr = new int[n];
//				for (int i = 0; i < n; i++) {
//					arr[i] = Integer.parseInt(str[i]);
//				}
//			}
//			return;

//		first();
//		sec();
//		third();
//		four();
		fif();
//			six();
	}

	private static void first() throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int t = Integer.parseInt(br.readLine());
		StringBuilder sb = new StringBuilder();

		while (t-- > 0) {
			String str = br.readLine();
			int n = str.length();
			sb.append(str.length() + "\n");
		}
		System.out.println(sb);
		return;
	}

	private static void sec() throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int t = Integer.parseInt(br.readLine());
		StringBuilder sb = new StringBuilder();
		while (t-- > 0) {
			String[] scn = (br.readLine()).trim().split(" ");
			int n = Integer.parseInt(scn[0]);
			long sum = 1;
			int count = 1;
			while (sum < n) {
				count += 1;
				sum += count;
			}
			if (sum - n == 1) {
				count += 1;
			}
			sb.append(count + "\n");
		}
		System.out.println(sb);
		return;
	}

	private static void third() throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int t = Integer.parseInt(br.readLine());
		StringBuilder sb = new StringBuilder();

		while (t-- > 0) {
			String[] scn = (br.readLine()).trim().split(" ");
			int n = Integer.parseInt(scn[0]);
			int m = Integer.parseInt(scn[1]);
			sb.append((n - 1) + " " + (m));
			sb.append("\n");

		}
		System.out.println(sb);
		return;
	}

	private static void four() throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int t = Integer.parseInt(br.readLine());
		StringBuilder sb = new StringBuilder();
		while (t-- > 0) {
			String[] scn = (br.readLine()).trim().split(" ");
			int n = Integer.parseInt(scn[0]);
			int x = Integer.parseInt(scn[1]);

			int[] arr = new int[n];
			scn = (br.readLine()).trim().split(" ");
			for (int i = 0; i < n; i++) {
				arr[i] = Integer.parseInt(scn[i]);
			}
			if (n == 2) {
				if (arr[0] <= arr[1]) {
					sb.append("0");
				} else {
					if (arr[0] > x && x <= arr[1]) {
						sb.append("1");
					} else {
						sb.append("-1");
					}
				}
				sb.append("\n");
				continue;

			}

			boolean can = true;
			int ans = 0;
			int prev = arr[0];
			for (int i = 1; i < n; i++) {
				if (arr[i] >= prev) {
					prev = arr[i];
				} else {
					int j = i - 2;
					boolean great = false;
					if (j >= 0 && arr[j] <= arr[i]) {
						int k = j;
						while (k >= 0) {
							if (arr[k] > x) {
								k -= 1;
								great = true;
							} else {
								break;
							}
						}
						if (!great) {
							if (i - 1 > 0 && x < arr[i - 1] && x <= arr[i]) {
								ans += 1;
								int temp = x;
								x = arr[i - 1];
								arr[i - 1] = temp;
							}
						} else {
							k += 1;
							ans += j - k + 2;
							while (k <= j) {
								int temp = arr[k];
								arr[k] = x;
								x = temp;
								k += 1;
							}
							int temp = arr[k];
							arr[k] = x;
							x = temp;
							k += 1;
						}
					} else {
						can = false;
						break;
					}
				}
			}
			if (can) {
				sb.append(ans);
			} else {
				sb.append("-1");
			}
			sb.append("\n");

		}
		System.out.println(sb);
		return;
	}

	private static void fif() throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int t = Integer.parseInt(br.readLine());
		StringBuilder sb = new StringBuilder();

		while (t-- > 0) {
			String[] scn = (br.readLine()).trim().split(" ");
			int n = Integer.parseInt(scn[0]);
			int x = Integer.parseInt(scn[1]);

			int[] arr = new int[n];
			scn = (br.readLine()).trim().split(" ");
			for (int i = 0; i < n; i++) {
				arr[i] = Integer.parseInt(scn[i]);
			}
			if (n == 2) {
				if (arr[0] <= arr[1]) {
					sb.append("0");
				} else {
					if (arr[0] > x && x <= arr[1]) {
						sb.append("1");
					} else {
						sb.append("-1");
					}
				}
				sb.append("\n");
				continue;

			}
			int ans = 0;
			int prev = arr[0];
			for (int i = 1; i < n; i++) {
				if (arr[i] >= prev) {
					prev = arr[i];
				} else {
					for (int j = 0; j < i; j++) {
						if (arr[j] > x) {
							int temp = x;
							x = arr[j];
							arr[j] = temp;
							ans += 1;
						}
					}
				}
			}
			prev = arr[0];
			boolean can = true;
			for (int i = 1; i < n; i++) {
				if (arr[i - 1] > arr[i]) {
					can = false;
					break;
				}
			}

			if (can) {
				sb.append(ans);
			} else {
				sb.append("-1");
			}
			sb.append("\n");
		}
		System.out.println(sb);
		return;
	}

	private static void six() throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int t = Integer.parseInt(br.readLine());
		StringBuilder sb = new StringBuilder();

		while (t-- > 0) {
			String[] scn = (br.readLine()).trim().split(" ");
			int n = Integer.parseInt(scn[0]);
			int[] arr = new int[n];
			scn = (br.readLine()).trim().split(" ");
			for (int i = 0; i < n; i++) {
				arr[i] = Integer.parseInt(scn[i]);
			}

		}
		System.out.println(sb);
		return;
	}
}
