(CODECHEF)chef_and_linear_chess.cpp

#include <bits/stdc++.h>
#include <set>
#include <cstdlib>
using namespace std;
// #include <ext/pb_ds/assoc_container.hpp>
// using namespace __gnu_pbds;
#include<algorithm>

#define ff              first
#define ss              second
#define int             long long
#define pb              push_back
#define mp              make_pair
#define pii             pair<int,int>
#define vi              vector<int>
#define mii             map<int,int>
#define pqb             priority_queue<int>
#define pqs             priority_queue<int,vi,greater<int> >
#define setbits(x)      __builtin_popcountll(x)
#define zrobits(x)      __builtin_ctzll(x)
#define mod             1000000007
#define inf             1e18
#define ps(x,y)         fixed<<setprecision(y)<<x
#define mk(arr,n,type)  type *arr=new type[n];
#define w(x)            int x; cin>>x; while(x--)
#define FIO             ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)



int32_t main() {
	FIO;
// #ifndef ONLINE_JUDGE
// 	freopen("input.txt", "r", stdin);
// 	freopen("output.txt", "w", stdout);
// #endif
	w(x) {
		int n, k; cin >> n >> k;
		int a[n];
		for (int i = 0; i < n; ++i)
			cin >> a[i];
		int ans = -1;
		for (int i = 0; i < n; ++i)
			if (a[i] <= k && k % a[i] == 0)
				ans = max(a[i], ans);

		cout << ans << "\n";




	}


	return 0;
}