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 sys,math
from collections import deque,defaultdict
import operator as op
from functools import reduce

#sys.setrecursionlimit(10**6) 

I=sys.stdin.readline

 #s="abcdefghijklmnopqrstuvwxyz"

"""
x_move=[-1,0,1,0,-1,1,1,-1]
y_move=[0,1,0,-1,1,1,-1,-1]
"""
def ii():
	return int(I().strip())
def li():
	return list(map(int,I().strip().split()))
def mi():
	return map(int,I().strip().split())

def ncr(n, r):
    r = min(r, n-r)
    numer = reduce(op.mul, range(n, n-r, -1), 1)
    denom = reduce(op.mul, range(1, r+1), 1)
    return numer // denom

def gcd(x, y):
    while y:
        x, y = y, x % y
    return x

def valid(row,col,rows,cols,rcross,lcross):
 	return rows[row]==0 and cols[col]==0 and rcross[col+row]==0 and lcross[col-row]==0


def div(n):
	tmp=[]
	for i in range(2,int(n**.5)+1):
		if n%i==0:
			cnt=0
			while(n%i==0):
				n=n//i 
				cnt+=1
			tmp.append((i,cnt))
	return tmp



def main():
	ans=""
	for _ in range(ii()):
		n,x=mi()
		arr=li()
		
		cnt=0
		flag=0
		while (sorted(arr)!=arr):
			cnt+=1	
			for i in range(n):
				if arr[i]>x:
					arr[i],x=x,arr[i]
					break
					
			else:
				flag=1
				break

		if flag:
			ans+="-1\n"	
		else:
			ans+=str(cnt)+"\n"



	print(ans)
	
	

		
	

		




		




			












			
		
			



		


	
			
						
			








	





			
		



	
			





	

























	
	
	





if __name__ == '__main__':
	main()