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 TEST
{
    static class Reader
    {
        final private int BUFFER_SIZE = 1 << 16;
        Scanner scan = new Scanner(new BufferedReader(new InputStreamReader(System.in)));
        private DataInputStream din;
        private byte[] buffer;
        private int bufferPointer, bytesRead;
        public Reader() 
        {
            din = new DataInputStream(System.in);
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }
        public Reader(String file_name) throws IOException 
        {
            din = new DataInputStream(new FileInputStream(file_name));
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }
        public String nextString() throws IOException
        {
            String str00 = scan.next();
            return str00;
        }
        public String readLine() throws IOException
        {
            byte[] buf = new byte[64];
            int cnt = 0, c;
            while ((c = read()) != -1)  
            {
                if (c == '\n')
                    break;
                buf[cnt++] = (byte) c;
            }
            return new String(buf, 0, cnt);
        }
        String next() throws IOException 
        {
            int c;
            for (c = read(); c <= 32; c = read());
            StringBuilder sb = new StringBuilder();
            for (; c > 32; c = read())
            {
                sb.append((char) c);
            }
            return sb.toString();
        }
        public int nextInt() throws IOException 
        {
            int ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do 
            {
                ret = ret * 10 + c - '0';
            } while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        } 
        public long nextLong() throws IOException 
        {
            long ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            }
            while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        }
        public double nextDouble() throws IOException
        {
            double ret = 0, div = 1;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            }
            while ((c = read()) >= '0' && c <= '9');           
            if (c == '.')
            {
                while ((c = read()) >= '0' && c <= '9')
                {
                    ret += (c - '0') / (div *= 10);
                }
            } 
            if (neg)
                return -ret;
            return ret;
        }
        private void fillBuffer() throws IOException 
        {
            bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
            if (bytesRead == -1)
                buffer[0] = -1;
        }
        private byte read() throws IOException 
        {
            if (bufferPointer == bytesRead)
                fillBuffer();
            return buffer[bufferPointer++];
        } 
        public void close() throws IOException 
        {
            if (din == null)
                return;
            din.close();
        }
        public int[] nextArray(int n) throws IOException 
        {
            int[] a=new int[n];
            for (int i=0;i<n;i++)
            {
                a[i]=nextInt();
            }
            return a;
        }
        public long[] nextArrayl(int n) throws IOException 
        {
            long[] a = new long[n];
            for (int i=0;i<n;i++)
            {
                a[i]=nextLong();
            }
            return a;
        }
    }
    public static boolean isSorted(int a[])
    {
        for(int i=1;i<a.length;i++)
        {
            if(a[i]<a[i-1])
            {
                return false;
            }
        }
        return true;
    }
    public static void main(String args[])throws IOException
    {
        Reader r=new Reader();
        int t=r.nextInt();
        while(t-->0)
        {
            int n=r.nextInt();
            int x=r.nextInt();
            int a[]=r.nextArray(n);
            int c=0,flag=1;
            while(flag==1)
            {
                if(isSorted(a))
                {
                    break;
                }
                flag=0;
                for(int i=0;i<n;i++)
                {
                    if(a[i]<=x)
                    {
                        continue;
                    }
                    else
                    {
                        a[i]=a[i]+x;
                        x=a[i]-x;
                        a[i]=a[i]-x;
                        c++;
                        flag=1;
                    }
                    if(isSorted(a))
                    {
                        flag=0;
                        break;
                    }
                }
            }
            if(!isSorted(a))
            {
                System.out.println(-1);
            }
            else
            {
                System.out.println(c);
            }
        }
    }
}