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
//clear adj and visited vector declared globally after each test case
//check for long long overflow
//while adding and subs check if mod becomes -ve
//while using an integer directly in a builtin function add ll
//Mod wale question mein last mein if dalo ie. Ans<0 then ans+=mod;
//Dont keep array name as size or any other key word

#include <bits/stdc++.h>
#include <algorithm>
#include <cmath>
using namespace std;
#define Fio                           \
    ios_base::sync_with_stdio(false); \
    cin.tie(nullptr);                 \
    cout.tie(nullptr)
#define f(i, n) for (long long int i = 0; i < n; i++)
#define ll long long int
#define fo(i, a, b) for (long long int i = a; i <= b; i++)
#define w(t)  \
    int t;    \
    cin >> t; \
    while (t--)
#define vi vector<int>
#define vl vector<long long int>
#define vvi vector<vector<int>>
#define vvl vector<vector<long long int>>
#define mii map<int, int>
#define umii unordered_map<int, int>
#define mll map<ll,ll>
#define umll unordered_map<ll,ll>
#define newl cout<<"\n"
#define pb push_back
#define mp make_pair
#define fi first
#define se second
const ll inf = 1e9 + 7;
const ll mod = 998244353;
#define MAX 501

ll mini(ll a,ll b){
    if(a>=b)return b;
    return a;
}

ll maxi(ll a,ll b){
    if(a>=b)return a;
    return b;
}

int notsorted(vl &A,ll n){
    fo(i,1,n-1){
        if(A[i]>A[i+1])return 1;
    }
    return 0;

}

int main(){
    Fio;
    w(t){
        ll n,x;
        cin>>n>>x;
        vl A(n+1);
        fo(i,1,n)cin>>A[i];
        ll ans = 0;
        while(notsorted(A,n)){
            ans++;
            ll i = 0;
            while(i<n && A[i]<=x)i++;
            if(i==n){
                ans = -1;
                break;
            }
            swap(A[i],x);
        }
        cout<<ans;
        newl;
    }
    return 0;
}     