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

/** Seek God..Trust God..Praise God..**/

#include<bits/stdc++.h>
using namespace std;


#define fRead(x)        freopen("x.txt","r",stdin)
#define fWrite(x)       freopen ("x.txt","w",stdout)

#define mt              make_tuple
#define ld              long double
#define ll              long long
#define ull             unsigned long long
#define ff              first
#define ss              second
#define pb              push_back
#define INF             2e16
#define PI              acos(-1.0)
#define mp              make_pair
#define pii             pair<int,int>
#define pll             pair<LL,LL>
#define endl            "\n";

#define min3(a,b,c)     min(a,min(b,c))
#define max3(a,b,c)     max(a,max(b,c))
#define min4(a,b,c,d)   min(a,min(b,min(c,d)))
#define max4(a,b,c,d)   max(a,max(b,max(c,d)))
#define SQR(a)          ((a)*(a))
#define FOR(i,a,b)      for(int i=a;i<=b;i++)
#define ROF(i,a,b)      for(int i=a;i>=b;i--)
#define REP(i,b)        for(int i=0;i<b;i++)
#define MEM(a,x)        memset(a,x,sizeof(a))
#define ABS(x)          ((x)<0?-(x):(x))

#define SORT(v)         sort(v.begin(),v.end())
#define REV(v)          reverse(v.begin(),v.end())


#define FASTIO        ios_base::sync_with_stdio(0);cin.tie(nullptr);




///..................Sort by second element in a pair in decending order............. ///
bool SortbySecDesc(const pair<long long,long long > &a, const pair<long long,long long > &b)
{
    return a.second>b.second;
}

///.........................first element of pair in descending order..........................//////
bool sortinrev(const pair<int,int> &a,
               const pair<int,int> &b)
{
    return (a.first > b.first);
}



///.............................................................TEMPLATE................................................./////



/*
long long  Prime[3000000],nPrime;
long long  mark[10000002];

void seive(long long int n)
{
	long long int i,j,limit=sqrt(n*1.0)+2;
	mark[1]=1;
	for(i=4; i<=n ;i+=2)
	mark[i]=1;
	Prime[nPrime++]=2;
	for(i=3; i<=n; i+=2)
	{
		if(!mark[i])
		{
			Prime[nPrime++]=i;
			if(i<=limit)
			{
				for(j=i*i; j<=n ;j+=i*2)
				{
					mark[j]=1;
				}
			}
		}
	}
}
*/
//asdasd

int main()
{
    FASTIO;

    ll t;

    cin >> t;

    while(t--)
    {

        ll n, x , i , j , k , l;


        cin >> n >> x;


        vector<ll>a;



        for(i=0; i<n; i++)
        {

            ll p;

            cin >> p;

            a.pb(p);
        }

        if(is_sorted(a.begin(),a.end()))
        {
            cout << 0 << endl;
            continue;

        }

        ll cnt = 0;


        for(i=0; i<n; i++)
        {
            if(a[i]>x)
            {


                cnt++;


                swap(x,a[i]);




                if(is_sorted(a.begin(),a.end()))
                {
                    break;
                }
            }
        }

        if(i==n)
        {
            cout << -1 << endl;
            continue;
        }
        else
        {
            cout << cnt << endl;


        }
    }








    return 0;
}
