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.*;
import java.math.*;
 public class File {
     static long max=0;
     static int target;
	public static void main(String[] args) throws Exception {
		FastIO io = new FastIO(); 
		int test=io.nextInt();
		while(test>0)
		{
		    int n=io.nextInt();
		    int x=io.nextInt();
		    int arr[]=new int[n];
		    for(int i=0;i<n;i++)arr[i]=io.nextInt();
		    if(check(arr)){
		        io.println(0);
		        test--;
		        continue;
		    }
		    int i=0,c=0;
		    while(i<n)
		    {
		        if(arr[i]>x)
		        {
		            int temp=x;
		            x=arr[i];
		            arr[i]=temp;
		            i++;
		            c++;
		        }
		        else i++;
		        if(check(arr))break;
		    }
		    if(check(arr))io.println(c);
		    else io.println(-1);
		    test--;
		}
		io.close();
	}
	static boolean check(int arr[])
	{
	    for(int i=0;i<arr.length-1;i++)
	    {
	        if(arr[i]>arr[i+1])return false;
	    }
	    return true;
	}
}
 class FastIO extends PrintWriter {
	private InputStream stream;
	private byte[] buf = new byte[1<<16];
	private int curChar, numChars;
 
	// standard input
	public FastIO() { this(System.in,System.out); }
	public FastIO(InputStream i, OutputStream o) {
		super(o);
		stream = i;
	}
	// file input
	public FastIO(String i, String o) throws IOException {
		super(new FileWriter(o));
		stream = new FileInputStream(i);
	}
 
	// throws InputMismatchException() if previously detected end of file
	private int nextByte() {
		if (numChars == -1) throw new InputMismatchException();
		if (curChar >= numChars) {
			curChar = 0;
			try {
				numChars = stream.read(buf);
			} catch (IOException e) {
				throw new InputMismatchException();
			}
			if (numChars == -1) return -1; // end of file
		}
		return buf[curChar++];
	}
 
	public String nextLine() {
		int c; do { c = nextByte(); } while (c <= '\n');
		StringBuilder res = new StringBuilder();
		do { res.appendCodePoint(c); c = nextByte(); } while (c > '\n');
		return res.toString();
	}
 
	public String next() {
		int c; do { c = nextByte(); } while (c <= ' ');
		StringBuilder res = new StringBuilder();
		do { res.appendCodePoint(c); c = nextByte(); } while (c > ' ');
		return res.toString();
	}
 
	public int nextInt() { 
		int c; do { c = nextByte(); } while (c <= ' ');
		int sgn = 1; if (c == '-') { sgn = -1; c = nextByte(); }
		int res = 0;
		do {
			if (c < '0' || c > '9')
				throw new InputMismatchException();
			res = 10*res+c-'0';
			c = nextByte();
		} while (c > ' ');
		return res * sgn;
	}
 
  public long nextLong() { 
		int c; do { c = nextByte(); } while (c <= ' ');
		long sgn = 1; if (c == '-') { sgn = -1; c = nextByte(); }
		long res = 0;
		do {
			if (c < '0' || c > '9')
				throw new InputMismatchException();
			res = 10*res+c-'0';
			c = nextByte();
		} while (c > ' ');
		return res * sgn;
	}
 
	public double nextDouble() { return Double.parseDouble(next()); }
}