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
#include<bits/stdc++.h>
using namespace std;
#define ff              first
#define ss              second
#define pb              push_back
#define mp              make_pair
#define ll 				long long
#define pii             pair<ll,ll>
#define vi              vector<ll>
#define mii               map<ll,ll>
#define pqi             priority_queue<ll>			//max pq
#define pqd             priority_queue<ll,vi,greater<ll> >
#define setbits(x)      __builtin_popcountll(x)
#define zrobits(x)      __builtin_ctzll(x)
#define MOD             1000000007
#define inf             1e18
#define ps(x,y)         fixed<<setprecision(y)<<x
#define pw(b,p)         pow(b,p) + 0.1
#define f(i,k,n)			for(ll i=k;i<n;i++)

ll power(ll a, ll b, ll mod) {ll res = 1; a %= mod; assert(b >= 0); for (; b; b >>= 1) {if (b & 1)res = res * a % mod; a = a * a % mod;} return res;}
ll power(ll a, ll b) {ll res = 1; assert(b >= 0); for (; b; b >>= 1) {if (b & 1)res = res * a ; a = a * a;} return res;}
ll min( ll a,  ll b) { return (a < b) ? a : b;}
ll max(ll a, ll b) {return (a > b) ? a : b;}
ll gcd (ll a, ll b) {if (a == 0) return  b; return gcd(b % a, a);}



void bwayne()
{
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#ifndef ONLINE_JUDGE
	freopen("input.txt", "r", stdin);
	freopen("output2.txt", "w", stdout);
#endif
}
// ll n;
// cin >> n;
// vi a(n);
// f(i, 0, n) {
// 	cin >> a[i];
// }

// vector<vi> a(n,vector<vi>(m,0));
// f(i,0,n){
// 	f(j,0,m){
// 		cin>>a[i][j];
// 	}
// }
bool sorted(vi &a) {
	ll n = a.size();
	f(i, 1, n) {
		if (a[i] < a[i - 1]) return false;
	}
	return true;
}



void solve() {
	ll n, x;
	cin >> n >> x;
	vi a(n);
	f(i, 0, n) {
		cin >> a[i];
	}
	ll count = 0;
	if (sorted(a)) {
		cout << count << endl;
		return;
	}

	f(i, 0, n) {
		if (sorted(a)) {
			cout << count << endl;
			return;
		}
		if (a[i] > x) {
			ll temp = a[i];
			a[i] = x;
			x = temp;
			count++;
		}
		// f(j, 0, n) {
		// 	cout << a[j] << " ";
		// }
		// cout << endl;
	}
	if (sorted(a)) {
		cout << count << endl;
		return;
	}
	cout << -1 << endl;
	return;


}
int main()
{
	bwayne();// remember
	ll t = 1;
	cin >> t;

	for (ll tt = 1; tt <= t; tt++)
	{
		// cout << "Case #" << tt << ": ";
		solve();
	}

	return 0;
}