#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
 
#define ALL(obj) (obj).begin(),(obj).end()
#define SPEED cin.tie(0);ios::sync_with_stdio(false);
 
template<class T> using PQ = priority_queue<T>;
template<class T> using PQR = priority_queue<T,vector<T>,greater<T>>;
 
constexpr long long MOD = (long long)1e9 + 7;
constexpr long long MOD2 = 998244353;
constexpr long long HIGHINF = (long long)1e18;
constexpr long long LOWINF = (long long)1e15;
constexpr long double PI = 3.1415926535897932384626433;
 
template <class T> vector<T> multivector(size_t N,T init){return vector<T>(N,init);}
template <class... T> auto multivector(size_t N,T... t){return vector<decltype(multivector(t...))>(N,multivector(t...));}
template <class T> void corner(bool flg, T hoge) {if (flg) {cout << hoge << endl; exit(0);}}
template <class T, class U>ostream &operator<<(ostream &o, const map<T, U>&obj) {o << "{"; for (auto &x : obj) o << " {" << x.first << " : " << x.second << "}" << ","; o << " }"; return o;}
template <class T>ostream &operator<<(ostream &o, const set<T>&obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr) o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;}
template <class T>ostream &operator<<(ostream &o, const multiset<T>&obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr) o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;}
template <class T>ostream &operator<<(ostream &o, const vector<T>&obj) {o << "{"; for (int i = 0; i < (int)obj.size(); ++i)o << (i > 0 ? ", " : "") << obj[i]; o << "}"; return o;}
template <class T, class U>ostream &operator<<(ostream &o, const pair<T, U>&obj) {o << "{" << obj.first << ", " << obj.second << "}"; return o;}
void print(void) {cout << endl;}
template <class Head> void print(Head&& head) {cout << head;print();}
template <class Head, class... Tail> void print(Head&& head, Tail&&... tail) {cout << head << " ";print(forward<Tail>(tail)...);}
template <class T> void chmax(T& a, const T b){a=max(a,b);}
template <class T> void chmin(T& a, const T b){a=min(a,b);}
void YN(bool flg) {cout << (flg ? "YES" : "NO") << endl;}
void Yn(bool flg) {cout << (flg ? "Yes" : "No") << endl;}
void yn(bool flg) {cout << (flg ? "yes" : "no") << endl;}


template<class Operator> class DisjointSparseTable{
public:
	Operator Op;                            //Operator 演算子、型、単位元を持つ
	using typeNode = decltype(Op.unitNode); //nodeの型
	size_t depth;
	size_t length;
	vector<vector<typeNode>> node;
	vector<size_t> msb;

	DisjointSparseTable(const vector<typeNode>& vec) {
		for(depth = 0;(1<<depth)<=vec.size();++depth);
		length = (1<<depth);
		
		//msb
		msb.resize(length,0);
		for(int i = 0; i < length; ++i) for(int j = 0; j < depth; ++j) if(i>>j) msb[i] = j;

		//init value
		node.resize(depth,vector<typeNode>(length,Op.unitNode));
		for(int i = 0; i < vec.size(); ++i) node[0][i] = vec[i];

		for(int i = 1; i < depth; ++i) {
			for(int r = (1<<i),l = r-1; r < length; r += (2<<i),l = r-1){
				//init accumulate
				node[i][l] = node[0][l];
				node[i][r] = node[0][r];
				//accumulate
				for(int k = 1; k < (1<<i); ++k) {
					node[i][l-k] = Op.funcNode(node[i][l-k+1],node[0][l-k]);
					node[i][r+k] = Op.funcNode(node[i][r+k-1],node[0][r+k]);
				}
			}
		}
	}

	//[l,r)
	typeNode get(int l,int r) {
		r--;
		return (l>r||l<0||length<=r) ? Op.unitNode: (l==r ? node[0][l] : Op.funcNode(node[msb[l^r]][l],node[msb[l^r]][r]));
	}
};

//一点更新 区間最小
template<class typeNode> struct nodeGCD {
	typeNode unitNode = 0;
	typeNode funcNode(typeNode l,typeNode r){return ((r == 0) ? l : funcNode(r, l % r));}
};

//Greatest Common Divisor
long long GCD(long long a, long long b) {
    return ((b == 0) ? a : GCD(b, a % b));
}

int main() {
	int N; cin >> N;
	vector<ll> A(N);
	for(int i = 0; i < N; ++i) cin >> A[i];
	DisjointSparseTable<nodeGCD<ll>> dst(A);
	ll ans = 0;
	for(int i = 0; i < N; ++i) {
		chmax(ans,GCD(dst.get(0,i),dst.get(i+1,N)));
	}
	cout << ans << endl;
	return 0;
}


Measured memory_bytes: 20608