#include<bits/stdc++.h>
typedef long long   ll;
#define endl        '\n'
#define F           first
#define S           second
#define pb          push_back
#define yes         cout<<"YES\n"
#define no          cout<<"NO\n"
#define all(x)      x.begin(),x.end()
#define allr(x)     x.rbegin(),x.rend()
#define error1(x)   cerr<<#x<<" = "<<(x)<<endl
#define error2(a,b) cerr<<"("<<#a<<", "<<#b<<") = ("<<(a)<<", "<<(b)<<")\n";
#define coutall(v)  for(auto &it: v) cout<<it<<" "; cout<<endl;
#define _ASRafi__   ios::sync_with_stdio(false); cin.tie(0);
using namespace std;

void solve()
{
    ll n, k;
    cin >> n >> k;
    map<ll, ll> mp;
    for (int i = 0; i < n; i++)
    {
        ll x; cin >> x;
        mp[x]++;
    }
    set<pair<ll, ll>> st; // {cnt, val}
    for(int i = 1; i <= k; i++)
    {
        ll c = 0;
        for(int j = i; j <= k; j += i)
        {
            if(mp.find(j) != mp.end()) c += mp[j];
        }
        // cout << i << " -> " << c << endl;
        st.insert({c, i});
    }
    cout << st.begin()->S << endl;
    return;
}

int32_t main()
{
    _ASRafi__;
    int tc = 1;
    cin >> tc;
    for (int t = 1; t <= tc; t++)
    {
        // cout << "Case " << t << ": ";
        solve();
    }
    return 0;
}