#include <bits/stdc++.h>
#define ll long long 
using namespace std;

ll __gcd(ll a, ll b){
    if(b == 0)
        return a;
    return __gcd(b,a%b);
}

signed main()
{
    ll n ;
    cin >> n;
    
    ll a[100000+1];
    
    for(ll i=0;i<n;++i)
        cin >> a[i];
        
    sort(a,a+n);
        
    if(n==1){
        cout << a[0] + 1 << endl;
        return 0;
    }
    
    assert(n >= 2);
    ll prefix[100000+1]{0} , suffix[100000+1]{0};
    
    ll gcd = 0;
    for(ll i=0;i<n;++i){
        gcd = __gcd(gcd,a[i]);
        prefix[i] = gcd;
    }
    
    gcd = 0;
    for(ll i=n-1;i>=0;--i){
        gcd = __gcd(gcd,a[i]);
        suffix[i] = gcd;
    }
    
    if(a[0]%suffix[1]){
        cout << suffix[1] << endl;
    }
    else if(a[n-1]%prefix[n-2])
    {
        cout << prefix[n-2] << endl;
    }
    else{
    for(ll i=1;i<n-1;++i){
        ll preGcd = __gcd(suffix[i+1],prefix[i-1]);
        if(a[i]%preGcd)
            {
                cout << preGcd << endl;
                break;
            }
    }
    }   
    return 0;
}