#include <algorithm>
#include <array>
#include <bitset>
#include <cmath>
#include <functional>
#include <iostream>
#include <limits>
#include <list>
#include <map>
#include <numeric>
#include <set>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>

using namespace std;
using ll = int64_t;

#define pv(val) cerr << #val << '=' << (val) << endl
#define pvn(name_str, val) cerr << name_str << '=' << (val) << endl
#define pl cerr << '@' << __LINE__ << endl

#define rep(i, n) for (ll i = 0; i < (n); i++)
#define all(a) a.begin(), a.end()

ll constexpr MM = 1000000007ll;

template <class T> ostream& operator<<(ostream& os, vector<T> const& vec) {
    if (vec.empty()) {
        os << "{}";
    } else {
        os << '{';
        for (size_t i = 0; i < vec.size() - 1; i++)
            os << vec[i] << ", ";
        os << vec.back() << '}';
    }
    return os;
}

template <class T, size_t S>
ostream& operator<<(ostream& os, array<T, S> const& arr) {
    if (arr.empty()) {
        os << "{}";
    } else {
        os << '{';
        for (size_t i = 0; i < arr.size() - 1; i++)
            os << arr[i] << ", ";
        os << arr.back() << '}';
    }
    return os;
}

template <class T, class U>
ostream& operator<<(ostream& os, pair<T, U> const& p) {
    os << '(' << p.first << ", " << p.second << ')';
    return os;
}

namespace math {
ll gcd(ll u, ll v) {
    while (v != 0) {
        ll r = u % v;
        u = v;
        v = r;
    }
    return u;
}
ll lcm(ll m, ll n) {
    if ((0 == m) || (0 == n))
        return 0;

    return ((m / math::gcd(m, n)) * n);
}
} // namespace math

struct UnionFind {
    vector<ll> data;
    UnionFind(ll size) : data(size, -1) {
    }
    bool unionSet(ll x, ll y) {
        x = root(x);
        y = root(y);
        if (x != y) {
            if (data[y] < data[x])
                swap(x, y);
            data[x] += data[y];
            data[y] = x;
        }
        return x != y;
    }
    bool findSet(ll x, ll y) {
        return root(x) == root(y);
    }
    ll root(ll x) {
        return data[x] < 0 ? x : data[x] = root(data[x]);
    }
    ll size(ll x) {
        return -data[root(x)];
    }
};

template <class T, class U>
pair<T, U> operator+(pair<T, U> const& a, pair<T, U> const& b) {
    return pair<T, U>(a.first + b.first, a.second + b.second);
}

template <class T, class U>
pair<T, U> operator-(pair<T, U> const& a, pair<T, U> const& b) {
    return pair<T, U>(a.first - b.first, a.second - b.second);
}

ll bound(function<bool(ll)> f, ll ng, ll ok) {
    while (abs(ng - ok) > 1) {
        ll mid = (ng + ok) / 2;
        if (f(mid))
            ok = mid;
        else
            ng = mid;
    }

    return ok;
}

int main(void) {
    ll n;
    cin >> n;

    vector<ll> a(n);
    rep(i, n) cin >> a[i];

    vector<ll> l(n), r(n);
    l[0] = a[0];
    r[n - 1] = a[n - 1];
    rep(i, n - 1) {
        l[i + 1] = math::gcd(l[i], a[i + 1]);
        r[n - (i + 1) - 1] = math::gcd(r[n - i - 1], a[n - (i + 1) - 1]);
    }
    ll ans = -1;
    rep(i, n) {
        if (i == 0)
            ans = max(ans, r[1]);
        else if (i == n - 1)
            ans = max(ans, l[n - 2]);
        else {
            ans = max(ans, math::gcd(l[i - 1], r[i + 1]));
        }
    }

    cout << ans << endl;

    return 0;
}


Measured memory_bytes: 2560