#pragma GCC optimize("Ofast")
#include<bits/stdc++.h>
using namespace::std;
//struct __INIT{__INIT(){cin.tie(0);ios::sync_with_stdio(false);cout<<fixed<<setprecision(15);}} __init;
__attribute__((constructor))
void init(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	cout<<fixed<<setprecision(15);
}
// random_device rd;
// mt19937 mt(rd());
// #include <boost/numeric/interval.hpp>
// #include <boost/numeric/interval/io.hpp>
// #include <boost/intrusive/rbtree.hpp>
// #include <boost/geometry.hpp>
// #include <boost/geometry/geometries/linestring.hpp>
// #include <boost/geometry/geometries/polygon.hpp>
// #include <boost/geometry/geometries/point_xy.hpp>
// #include <boost/math/tools/minima.hpp>
// using boost::math::tools::brent_find_minima;
// #include <boost/multiprecision/cpp_dec_float.hpp>
// #include <boost/multiprecision/cpp_int.hpp>
// namespace mp = boost::multiprecision;
// typedef mp::number<mp::cpp_dec_float<256>> cdouble;
// typedef mp::cpp_int cint;

#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/priority_queue.hpp>
#include<ext/pb_ds/tag_and_trait.hpp>
using namespace __gnu_pbds;
template<typename T=long long>using pbds=tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
template<typename T=long long>using pbds_map=tree<T,T,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
template<typename T=long long>using pqueue =__gnu_pbds::priority_queue<T, less<T>,rc_binomial_heap_tag>;
typedef long long lint;
typedef long long ll;
typedef long double ldouble;
typedef vector<lint> vec;
typedef vector<vector<lint>> mat;
typedef vector<vector<vector<lint>>> mat3;
typedef vector<double> dvec;
typedef vector<vector<double>> dmat;
typedef vector<vector<vector<double>>> dmat3;
typedef vector<string> svec;
typedef vector<vector<string>> smat;
typedef vector<vector<vector<string>>> smat3;
typedef vector<pair<lint,lint>> pvec;
typedef vector<vector<pair<lint,lint>>> pmat;
typedef vector<vector<vector<pair<lint,lint>>>> pmat3;
#define rep(i, n) for(lint i = 0; i < (lint)(n); i++)
#define irep(i) for(lint i = 0;; i++)
#define irep1(i) for(lint i = 1;; i++)
#define irep2(i) for(lint i = 2;; i++)
#define rrep(i, n) for(lint i = (lint)(n-1); i >-1; i--)
#define rrepi(i,a,b) for(lint i = (lint)(b-1); i >a-1; i--)
#define repi(i,a,b) for(lint i=lint(a);i<lint(b);i++)
#define rep2(i,a,b,c) for(lint i=lint(a);i>lint(b);i+=c)
#define all(x) (x).begin(),(x).end()
//#define PI 3.141592653589793
#define dist(x1,y1,x2,y2) (pow(pow(x2-x1,2)+pow(y2-y1,2),0.5))
#define output(v) ({bool f=0;for(auto i:v){cout<<(f?" ":"");if(i>INF/2)cout<<"INF";else cout<<i;f=1;}cout<<"\n";})
#define output2(v) for(auto j:v)output(j);
#define _output(v) ({bool f=0;rep(i,v.size()){cout<<(f?" ":"");if(v[i]>INF/2)cout<<"INF";else cout<<v[i];f=1;}cout<<"\n";})
#define _output2(v) rep(j,v.size()){_output(v[j]);}
#define input(a,n) lint n;cin>>n;vector<lint>a(n);rep(i,n)cin>>a[i];
#define SUM(v) accumulate(all(v),0LL)
#define INF (1LL<<60)
#define IINF (1<<30)
#define EPS (1e-10)
#define LINF 9223372036854775807
#define MOD 100000007
#define endl "\n"
template<typename T=lint>T in(){return *istream_iterator<T>(cin);}
inline lint gcd(lint a,lint b){return b?gcd(b,a%b):a;}
template<typename T=lint>inline T lcm(T a,T b){return a/gcd(a,b)*b;}
template<typename T=lint>inline T add(T a,T b){return a+b;}
template<typename T=lint>inline T minq(T a,T b){return min(a,b);}
inline bool chmin(auto& s,const auto& t){bool res=s>t;s=min(s,t);return res;}
inline bool chmax(auto& s,const auto& t){bool res=s<t;s=max(s,t);return res;}
vector<lint> dx={-1,1,0,0,1,1,-1,-1};
vector<lint> dy={0,0,-1,1,1,-1,1,-1};

unsigned long rnd() {
	static unsigned long x=123456789, y=362436069, z=521288629, w=88675123;
	unsigned long t=(x^(x<<11));
	x=y; y=z; z=w;
	return ( w=(w^(w>>19))^(t^(t>>8)) );
}

template<typename T,typename E>
struct RBST{
    using F=function<E(E,E)>;
    vector<F> func;
    inline unsigned long rnd() {
        static unsigned long x=123456789, y=362436069, z=521288629, w=88675123;
        unsigned long t=(x^(x<<11));
        x=y; y=z; z=w;
        return ( w=(w^(w>>19))^(t^(t>>8)) );
    }
    struct node{
        node* ch[2]={nullptr,nullptr};
        T key;
        E val;
        RBST<T,E>* par;
        vector<E> vals;
        int cnt=1;
        node(T key,E val,RBST<T,E>* par):key(key),val(val),par(par){
            vals.resize(par->func.size());
            par->update(this);
        }
        operator E(){return val;}
        node& operator =(const T& v){val=v;return *this;}
    };
    using np=node*;
    np stk=nullptr;
    np root=nullptr;
    RBST(F f...){
        func.insert(func.end(),{f});
    }
    np emplace(T key,E val){
        reload();
        np res=new node(key,val,this);
        insert(res);
        return res;
    }
    size_t size(){
        reload();
        return count(root);
    }
    void erase_all(T key){
        reload();
        auto d=split(root,upper_bound(root,key));
        root=merge(split(d.first,lower_bound(d.first,key)).first,d.second);
    }
    np erase(T key){
        reload();
        auto tmp=get(key);
        if(!tmp)return nullptr;
        auto s=split(root,lower_bound(root,key));
        auto t=split(s.second,1);
        root=merge(s.first,t.second);
        return t.first;
    }
    vector<E> operator ()(const int& l,const int& r){
        reload();
        auto s=split(root,lower_bound(root,l));
        auto t=split(s.second,lower_bound(s.second,r));
        vector<E>res;
        if(t.first)res=t.first->vals;
        else res.resize(func.size(),E());
        root=merge(s.first,merge(t.first,t.second));
        return res;
    }
    E& operator[](const int& key){
        reload();
        auto d=get(key);
        if(d){
            stk=erase(d->key);
            return stk->val;
        }else {
            stk=new node(key,E(),this);
            return stk->val;
        }
    }
    int lower_bound(T k){reload();return lower_bound(root,k);}
    int upper_bound(T k){reload();return upper_bound(root,k);}
    bool binary_search(T k){reload();return get(k);}
    private:
    inline void insert(np n){
        if(!n)return;
        auto d=split(root,lower_bound(root,n->key));
        root=merge(d.first,merge(update(n),d.second));
    }
    inline np get(const int& k){
        pair<np,np>s,t;
        np res=(t=split((s=split(root,lower_bound(root,k))).second,1)).first;
        root=merge(s.first,merge(t.first,t.second));
        if(res&&res->key==k)return res;
        return nullptr;
    }
    inline int count(np t){return !t?0:t->cnt;}
    inline np update(np t){
        t->cnt=count(t->ch[0])+count(t->ch[1])+1;
        for(int i=0;i<(int)func.size();i++){
            t->vals[i]=t->val;
            if(t->ch[0])t->vals[i]=(func[i])(t->vals[i],t->ch[0]->vals[i]);
            if(t->ch[1])t->vals[i]=(func[i])(t->vals[i],t->ch[1]->vals[i]);
        }
        return t;
    }
    inline np merge(np l,np r){
        if(!l||!r)return !l?r:l;
        if((unsigned long)count(l)>rnd()%(unsigned long)(count(l)+count(r))){
            l->ch[1]=merge(l->ch[1],r);
            return update(l);
        }else{
            r->ch[0]=merge(l,r->ch[0]);
            return update(r);
        }
    }
    //kより小さい値の数
    inline int lower_bound(np t,T k){
        if(!t)return 0;
        if(k<=(t->key))return lower_bound(t->ch[0],k);
        else return count(t->ch[0])+1+lower_bound(t->ch[1],k);
    }
    //k以下の値の数
    inline int upper_bound(np t,T k){
        if(!t)return 0;
        if(k<(t->key))return upper_bound(t->ch[0],k);
        else return count(t->ch[0])+1+upper_bound(t->ch[1],k);
    }
    //0-indexedでk番目から右側に
    inline pair<np,np> split(np t,int k){
        if(!t)return make_pair(nullptr,nullptr);
        if(k<=count(t->ch[0])){
            auto s=split(t->ch[0],k);
            t->ch[0]=s.second;
            return make_pair(s.first,update(t));
        }else{
            auto s=split(t->ch[1],k-count(t->ch[0])-1);
            t->ch[1]=s.first;
            return make_pair(update(t),s.second);
        }
    }
    inline void reload(){
        if(stk){insert(stk);}
        stk=nullptr;
    }
    // inline np make_tree(vector<np> node_list){
    //     sort(all(node_list),[](const np& s,const np& t){
    //         return s->key < t->key;
    //     });
    //     function<np(int,int)> f=[&](int l,int r){
    //         if(l==r)return nullptr;
    //         lint mid=(l+r)/2;
    //         node_list[mid]->l=f(l,(l+r)/2);
    //         node_list[mid]->l=f((l+r)/2+1,r);
    //         update(node_list[mid]);
    //         return node_list[mid];
    //     };
    //     auto res=f(0,node_list.size());
    //     return res;
    // }
};

int main(){
    RBST<lint,lint>t(gcd);
    lint n;
    cin>>n;
    rep(i,n){
        lint x;
        cin>>x;
        t[i]=x;
    }
    lint mx=0;
    rep(i,n){
        chmax(mx,gcd(t(0,i)[0],t(i+1,n)[0]));
    }
    cout<<mx<<endl;
}

Measured memory_bytes: 13312