/* -*- coding: utf-8 -*-
 *
 * 2570.cc:  No.2570 最大最大公約数 - yukicoder
 */

#include<cstdio>
#include<vector>
#include<algorithm>
 
using namespace std;

/* constant */

const int MAX_N = 100;

/* typedef */

typedef long long ll;
typedef vector<ll> vl;

/* global variables */

ll as[MAX_N];

/* subroutines */

/* main */

int main() {
  int n, k;
  scanf("%d%d", &n, &k);
  for (int i = 0; i < n; i++) scanf("%lld", as + i);

  vl ds;
  for (int i = 0; i < n; i++)
    for (ll p = 1; p * p <= as[i]; p++)
      if (as[i] % p == 0) {
	ds.push_back(p);
	ll q = as[i] / p;
	if (q != p) ds.push_back(q);
      }

  sort(ds.begin(), ds.end());
  ds.erase(unique(ds.begin(), ds.end()), ds.end());

  ll maxg = 1;
  for (int i = ds.size() - 1; i >= 0; i--) {
    ll g = ds[i], sum = 0;
    for (int j = 0; j < n; j++) {
      ll r = as[j] % g;
      sum += min(r, g - r);
    }
    if (sum <= k) { maxg = g; break; }
  }

  printf("%lld\n", maxg);
  return 0;
}