#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
using namespace std;
typedef long long LL;
const int N = 55;
int T;
int now,nowsum,ans;
int b[N], f[N];
int main() {
    scanf("%d", &T);
    while (T--) {
        int a, n, m;
        scanf("%d%d", &n, &a);
        for (int i = 1;i <= n; ++i)    scanf("%d", &b[i]);
        sort(b + 1, b + n + 1);
        m = 1 << n;
        ans = 1e8;
        for (int t = 0;t < m; ++t) {
            for (int i = 1; i <= n; ++i) {
                if (((1<<(i-1))&t) != 0) f[i] = 1;
                else f[i ] =0;
            }
            now = a;
            nowsum = 0;
            for (int i = n; i >= 1; --i) {
                if (f[i] == 0) continue;
                now %= b[i];
                ++nowsum;
            }
            if (!now) ans = min(ans, nowsum);
        }
        if (ans == 1e8) ans=-1;
        printf("%d\n", ans);
    }
    return 0;
}