#include <cstdio>
#include <algorithm>
#include <functional>

using namespace std;

int n,nn,x;
int a[20];

bool can(int i) {
    int y=x;
    for (int j=0;i;j++,i>>=1) {
        if (i&1) y%=a[j];
    }
    if (y==0) return true;
    else return false;
}
int main() {
    int t;
    scanf("%d",&t);
    while (t--) {
        scanf("%d%d",&n,&x);
        for (int i=0;i<n;i++) scanf("%d",&a[i]);
        sort(a,a+n,greater<int>());
        int ans=n+1;
        nn=1<<n;
        for (int i=0;i<nn;i++) {
            if (can(i)) ans=min(ans,__builtin_popcount(i));
        }
        if (ans==n+1) printf("-1\n");
        else printf("%d\n",ans);
    }
    return 0;
}