#define PROB Training
#include <cstdio>
#include <cstring>
#include <algorithm>
using std::sort;
#include <vector>
#include <utility>
typedef std::pair<int,int> PII;

#define f(x,y,z) for(int x = (y),__ = (z);x < __;++x)
#define g(x,y,z) for(int x = (y),__ = (z);x <= __;++x)
#define gd(x,y,z) for(int x = (y),__ = (z);x >= __;--x)
#define CLR(X) memset(X,0,sizeof(X))
#define SET(ARR,X) memset(ARR,X,sizeof(ARR))
#define R(X,Y) f(X,0,Y)
#define G(x,y) g(X,0,Y)
#define MAXN 1024


#ifdef WIN32
    #define LLD "%I64d"
    #define LLU "%I64u"
#else
    #define LLD "%lld"
    #define LLU "%llu"    
#endif

typedef long long LL;
typedef long double real;

int t,n;
int a;
int b[MAXN];
int num,cnt,ans;
inline void solve(){
    ans = 100;
    f(i,0,1LL << n){
        num = a;cnt = 0;
        // puts("");
        f(j,0,n)if (i & (1 << j)){
            ++cnt;
            // printf("%d ",b[j]);
            num = num % b[j];
            if (num == 0){
                if (cnt <= ans)ans = cnt;
                break;
            }
        }
    }
    if (ans != 100)printf("%d\n",ans);
    else puts("-1");
}
inline bool cmp(int x,int y){
    return x > y;
}
int main(){
    scanf("%d",&t);
    while (t--){
        scanf("%d%d",&n,&a);
        f(i,0,n)scanf("%d",b + i);
        std::sort(b,b + n,cmp);
        solve();
    }
    return 0;
}