#define _CRT_SECURE_NO_WARNINGS
#include "bits/stdc++.h"

#define PB push_back
#define PF push_front
#define LB lower_bound
#define UB upper_bound
#define fr(x) freopen(x,"r",stdin)
#define fw(x) freopen(x,"w",stdout)
#define iout(x) printf("%d\n",x)
#define lout(x) printf("%lld\n",x)
#define REP(x,l,u) for(ll x = l;x<u;x++)
#define RREP(x,l,u) for(ll x = l;x>=u;x--)
#define complete_unique(a) a.erase(unique(a.begin(),a.end()),a.end())
#define mst(x,a) memset(x,a,sizeof(x))
#define all(a) a.begin(),a.end()
#define PII pair<int,int>
#define PLL pair<ll,ll>
#define MP make_pair
#define sqr(x) ((x)*(x))
#define lowbit(x) ((x)&(-(x)))
#define lson (ind<<1)
#define rson (ind<<1|1)
#define se second
#define fi first
#define sz(x) ((int)x.size())
#define EX0 exit(0);

typedef  long long ll;
typedef unsigned long long ull;
typedef double db;
typedef long double ld;
using namespace std;
typedef vector<ll> VLL;
typedef vector<int> VI;
const int block_size = 320;
typedef complex<ll> point;
const ll mod = 1e9 + 7;
const ll inf = 1e9 + 7;
const ll INF = 1e15;
const ld eps = 1e-9;
const db PI = atan(1) * 4;

template<typename T, typename S>inline bool upmin(T&a, const S&b) { return a > b ? a = b, 1 : 0; }
template<typename T, typename S>inline bool upmax(T&a, const S&b) { return a < b ? a = b, 1 : 0; }

ll gcd(ll a, ll b) { return b == 0 ? a : gcd(b, a%b); }
template<typename T>
T extgcd(T a, T b, T& x, T& y) {
	T d = a;
	if (b != 0) {
		d = extgcd(b, a%b, y, x);
		y -= (a / b) * x;
	}
	else {
		x = 1; y = 0;
	}
	return d;
}

ll pow(ll a, ll b) {
	if (b == 0) {
		return 1;
	}
	if (b == 1) {
		return a;
	}
	ll ans = pow(a, b / 2);
	ans *= ans;
	ans *= b % 2 == 1 ? a : 1;
	return ans;
}

namespace SOLVE {
	VI A;

	ll GCD(int a, int b) {
		if (a == -1 && b == -1) {
			return -1;
		}
		if (a == -1) {
			return b;
		}
		if (b == -1) {
			return a;
		}
		return gcd(a, b);
	}

	struct SegTree {
		static const int maxn = 100000;

		struct node {
			int l, r, value;
		};

		node no[maxn * 4];
		void push_up(int ind) {
			no[ind].value = GCD(no[lson].value, no[rson].value);
		}
		void push_down(int ind) {
		}
		void build(int l, int r, int ind) {
			no[ind].l = l;
			no[ind].r = r;
			no[ind].value = -1;
			if (l == r) {
				no[ind].value = A[l];
			}
			else {
				int mid = (l + r) / 2;
				build(l, mid, lson);
				build(mid + 1, r, rson);
				push_up(ind);
			}
		}
		
		void query(int l, int r, int ind, int& ans) {
			if (l > no[ind].r || r < no[ind].l) {
				ans = -1;
				return;
			}
			if (l <= no[ind].l && no[ind].r <= r) {
				ans = no[ind].value;
			}
			else {
				int ans1, ans2;
				push_down(ind);
				query(l, r, lson, ans1);
				query(l, r, rson, ans2);
				push_up(ind);
				ans = GCD(ans1, ans2);
			}
		}
	};

	SegTree tree;

	void main() {
		int n;
		int ans = -1;
		cin >> n;
		A.resize(n);
		REP(i, 0, n) {
			cin >> A[i];
			ans = GCD(ans, A[i]);
		}
		tree.build(0, n - 1, 1);

		int thisgcd, ans1, ans2;
		REP(i, 0, n) {
			tree.query(0, i - 1, 1, ans1);
			tree.query(i + 1, n - 1, 1, ans2);
			thisgcd = GCD(ans1, ans2);
			ans = max(ans, thisgcd);
		}
		cout << ans << endl;
	}
}


signed main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);

	int t;
	//    in(t);
	t = 1;
	while (t--) {
		SOLVE::main();

	}

	return 0;
}


Measured memory_bytes: 4736