#include <stdio.h>
#include <string.h>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <string>
#include <math.h>
#include <stdlib.h>
#include <time.h>
using namespace std;

int a, n;
int num[26];
int ans;

void dfs(int cur, int x, int tim) {
    if(x == 0) {
        ans = min(ans, tim);
        return;
    }
    if(cur < 0) return;
    for(int i = cur; i >= 0; --i) {
        dfs(i-1, x%num[i], tim+1);
    }
}

int main()
{
    //freopen("out", "w", stdout);
    //freopen("in", "r", stdin);
    int cases;
    scanf("%d", &cases);
    while(cases--) {
        scanf("%d%d", &n, &a);
        for(int i = 0; i < n; ++i) {
            scanf("%d", &num[i]);
        }
        sort(num, num+n);
        ans = 1e7;
        dfs(n-1, a, 0);
        if(ans == 1e7) ans = -1;
        printf("%d\n", ans);
    }
    return 0;
}