#include <set>
#include <map>
#include <queue>
#include <stack>
#include <cmath>
#include <string>
#include <cctype>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iomanip>
#include <sstream>
#include <iostream>
#include <algorithm>
using namespace std;
#define ls id<<1,l,mid
#define rs id<<1|1,mid+1,r
#define OFF(x) memset(x,-1,sizeof x)
#define CLR(x) memset(x,0,sizeof x)
#define MEM(x) memset(x,0x3f,sizeof x)
typedef long long ll ;
typedef pair<int,int> pii ;
const int maxn = 1e5+50 ;
const int inf = 0x3f3f3f3f ;
const int MOD = 1e9+7 ;
int n,a,num[50],ans;
int vis[50];
bool cmp(const int &a,const int &b) {return a>b;}

void dfs(int now,int step) {
    if (step>=n) return ;
    for (int i=0;i<n;i++) {
        if (num[i]>now||vis[i]) continue ;
        if (now%num[i]==0) {
            ans=min(ans,step+1);
        }
        vis[i]=1;
        dfs(now%num[i],step+1);
        vis[i]=0;
    }
}

int main () {
#ifdef LOCAL
    freopen("C:\\Users\\Administrator\\Desktop\\in.txt","r",stdin);
//      freopen("C:\\Users\\Administrator\\Desktop\\out.txt","w",stdout);
#endif
    int T;
    scanf("%d",&T);
    while (T--) {
        CLR(vis);
        ans=inf;
        scanf("%d%d",&n,&a);
        for (int i=0;i<n;i++) scanf("%d",num+i);
        sort(num,num+n,cmp);
        int s=1<<n ;
        for (int i=0;i<s;i++) {
            int d=a;
            for (int j=0;j<n;j++) {
                if (i&1<<j) d%=num[j];
            }
            if (d==0) ans=min(ans,__builtin_popcount(i));
        }
        if (ans>1000000) printf("-1\n");
        else printf("%d\n",ans);
    }
    return 0;
}