#include <cstring>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <cassert>
#include <iomanip>

using namespace std;

#define repu(i, a, b) for (int i = (a); i < (b); ++i)
#define repd(i, a, b) for (int i = (a); i > (b); --i)
#define mem(a, x) memset(a, x, sizeof(a))
#define all(a) a.begin(), a.end()
#define uni(a) a.erase(unique(all(a)), a.end())
#define count_bits(x) __builtin_popcount(x)
#define count_bitsll(x) __builtin_popcountll(x)

typedef long long ll;
const int MOD = 1000000007;

template<class T, class U> inline T tmin(T a, U b) {return (a < b) ? a : b;}
template<class T, class U> inline T tmax(T a, U b) {return (a > b) ? a : b;}
template<class T, class U> inline void amax(T &a, U b) {if (b > a) a = b;}
template<class T, class U> inline void amin(T &a, U b) {if (b < a) a = b;}
template<class T> inline T tabs(T a) {return (a > 0) ? a : -a;}
template<class T> T gcd(T a, T b) {while (b != 0) {T c = a; a = b; b = c % b;} return a;}

const int N = 20;
int a[N], b[N];

int main(int argc, char *argv[]) {
    ios_base::sync_with_stdio(false);
    
    int ntest, n, A;
    
    cin >> ntest;
    while (ntest--) {
        cin >> n >> A;
        repu(i, 0, n) cin >> a[i];
        sort(a, a + n);
        int ret = -1;
        repu(i, 1, (1 << n)) {
            int cnt = 0;
            repu(j, 0, n) {
                if (i & (1 << j)) b[cnt++] = a[j];
            }
            int x = A;
            repd(j, cnt - 1, -1) x %= b[j];
            if (x == 0) {
                ret = cnt; break;
            }
        }
        printf("%d\n", ret);
    }
    
    return 0;
}