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
//  Created by Ganesh Medewar
//  Copyright © 2020 Ganesh Medewar. All rights reserved.
//  $ ø h @ m
#include<bits/stdc++.h>
#define ll          long long
#define db          double
#define pb          push_back
#define pf          push_front
#define mp          make_pair
#define vll         vector <ll>
#define pll         pair<ll,ll>
#define vstr        vector<string>
#define vchar       vector<char>
#define ALL(a)      (a).begin(),(a).end()
#define ft          first
#define sd          second
#define sz          size()
#define mll         map<ll,ll>
#define vpll        vector<pair<ll,ll>>
#define umll        unordered_map<ll,ll>
#define sll         set<ll>
#define usll        unordered_set<ll>
#define spll        set<pair<ll,ll>>
#define mset(arr) memset(arr,0,sizeof(arr))
#define f(i,a,b) for(ll i=a;i<b;i++)
#define fr(i,a,b) for(ll i=a;i>=b;i--)
#define hs ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
const ll m=998244353;
const ll INF = LLONG_MAX;
const ll MOD=1e9+7;
const float pi=3.1415926535897932384626433832795028841971693993751058209749;
using namespace std;
ll prime(ll x){bool flag=1;for(ll i=2;i*i<=x;i++){if(x%i==0){flag=0;break;}}return flag;}
ll gcd(ll r,ll b){ll x=1;while(b!=0){x=b;b=r%b;r=x;}return x;}
ll po(ll x,ll y){ //power using modulo
    ll res=1;
    while(y){
        if(y%2)res=(res*x)%m;
        y/=2;x=(x*x)%m;}
    return res;
}
void io()
{
    #ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);freopen("output.txt", "w", stdout);
    #endif
}
void solve(){
    ll n,x;
    cin>>n>>x;
    vll v(n);
    f(i,0,n)cin>>v[i];
    ll cnt=0,ans=0;
    f(i,0,n-1){
        if(v[i]>v[i+1]){
            if(x>v[i+1]){
                cout<<-1<<endl;
                return;
            }else{
                cnt++;swap(x,v[i]);ans+=cnt;cnt=0;
            }
        }
        if(v[i]>x){
            cnt++;swap(x,v[i]);
        }
    }
    cout<<ans<<endl;
    return;
}
int main()
{
    //io();
    hs;
    ll t=1;
    cin>>t;
    while(t--)
    {solve();}
    return 0;
}
