#include "bits/stdc++.h"
using namespace std;
#define ll long long
#define endl '\n'
#define rep(i, n) for(int i = 0; i < (int)(n); i++)
#define rep2(i,a,b) for(int i=int(a);i<int(b);i++)
#define pb emplace_back
#define all(x) (x).begin(),(x).end()
int mod=1e9+7;
int mod2=998244353;
const int INF=1e9;

int gcd(int a, int b) {
  if(a < b) return gcd(b, a);
  int r;
  while ((r=a%b)) {
    a = b;
    b = r;
  }
  return b;
}

signed main(){
	ll n;
	cin>>n;
	vector<ll> a(n);
	rep(i,n)cin>>a[i];
	vector<ll> r(n);
	vector<ll> l(n);
	l[0]=a[0];
	r[n-1]=a[n-1];
	rep2(i,1,n)l[i]=gcd(l[i-1],a[i]);
	rep2(i,1,n)r[n-1-i]=gcd(r[n-i],a[n-1-i]);
	int ans=max(l[n-2],r[1]);
	rep2(i,0,n-2)ans=max(ans,gcd(l[i],r[i+2]));
	cout<<ans<<endl;
}

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