#include<iostream>
#include<cstdio>
#include<algorithm>
#include<queue>
#include<map>
#include<cstring>
#include<stdlib.h>
#include<vector>
#include<stack>
#include<math.h>
#define inf (0x3f3f3f3f)
using namespace std;


int n, a;
int b[21];
int c[21];

int cmp(int a, int b)
{
    return a > b;
}

int work(int i)
{
    int num=0;
    int temp = a;
    for (int j = 0; j < n; j++)
    {
        if (i>>j & 1)
        {
            temp %= b[j];
            num++;
        }
    }
    if (temp != 0)return inf;
    return num;
}

int main()
{
//    freopen("C:/Users/Administrator/Desktop/ACM/iotest/test.txt", "r", stdin);
    int T;
    scanf("%d", &T);
    while (T--)
    {
        int tar=inf;
        scanf("%d %d", &n, &a);
        for (int i = 0; i < n; i++)
            scanf("%d", b + i);
        sort(b, b + n,cmp);
        for (int i = 1; i <(1<<n); i++)
            tar = min(tar,work(i));

        if (tar == inf)
            printf("-1\n");
        else printf("%d\n", tar);
    }
}