#include <bits/stdc++.h>
using namespace std;
struct Fast {
    Fast() {
        std::cin.tie(0);
        ios::sync_with_stdio(false);
        cout.precision(20);
    }
} fast;

/* define */
#define FOR(I, X, Y) for(long long(I) = (X); (I) < (Y); (I)++)
#define REP(I, X, Y) for(long long(I) = (Y)-1; (I) >= (X); (I)--)
#define ALL(X) (X).begin(), (X).end()
#define pb push_back
#define COUNT(V, X)                                                            \
    (upper_bound((V).begin(), (V).end(), X) -                                  \
     lower_bound((V).begin(), (V).end(), X))
#define debug(x) cerr << #x << ':' << x << endl;
#define DEBUG(v)                                                               \
    {                                                                          \
        cerr << #v << ':';                                                     \
        for(auto xv : v) cerr << xv << ' ';                                    \
        cerr << endl;                                                          \
    }
#define Yes(X) cout << (X ? "Yes" : "No") << endl;
#define YES(X) cout << (X ? "YES" : "NO") << endl;
#define ctoi(C) (C - '0')
#define pow2(x) ((long long)((long long)1 << x))

/* alias */
using ll = long long;
using ld = long double;
using vi = vector<int>;
using vii = vector<vector<int>>;
using vl = vector<long long>;
using vll = vector<vector<long long>>;
using pi = pair<int, int>;
using pl = pair<long long, long long>;
template <typename T> using PQ = priority_queue<T>;
template <typename T> using minPQ = priority_queue<T, vector<T>, greater<T>>;

/* const */
const long long dx[] = {1, 0, -1, 0};
const long long dy[] = {0, 1, 0, -1};
const long long dx8[] = {1, 1, 0, -1, -1, -1, 0, 1};
const long long dy8[] = {0, 1, 1, 1, 0, -1, -1, -1};
const long long dx9[] = {1, 1, 0, -1, -1, -1, 0, 1, 0};
const long long dy9[] = {0, 1, 1, 1, 0, -1, -1, -1, 0};
const int INF = 1000000007;
const long long LINF = 1000000000000000007;

/* func */
template <typename T> inline bool chmin(T &a, const T &b) {
    if(a > b) a = b;
    return a > b;
}
template <typename T> inline bool chmax(T &a, const T &b) {
    if(a < b) a = b;
    return a < b;
}
long long max(long long x, int y) {
    return max(x, (long long)y);
}
long long max(int x, long long y) {
    return max((long long)x, y);
}
long long min(long long x, int y) {
    return min(x, (long long)y);
}
long long min(int x, long long y) {
    return min((long long)x, y);
}

/* liblary */

long long GCD(long long a, long long b) {
    long long q;
    while(b) {
        q = a % b;
        a = b;
        b = q;
    }
    return a;
}

struct SparseTable {
    vector<vector<long long>> table_GCD;
    vector<vector<long long>> table_max;
    vector<long long> log_table;
    SparseTable(const vector<long long> &A) : table_GCD(), table_max() {
        log_table.resize(A.size() + 1);
        log_table[1] = 0;
        for(long long i = 2; i <= A.size(); i++) {
            log_table[i] = log_table[i / 2] + 1;
        }
        table_GCD.resize(A.size());
        fill(table_GCD.begin(), table_GCD.end(),
             vector<long long>(log_table[A.size()] + 1));
        for(long long i = 0; i < A.size(); i++) table_GCD[i][0] = A[i];
        for(long long i = 1; (1 << i) <= A.size(); i++) {
            for(long long j = 0; j + (1 << i) <= A.size(); j++) {
                table_GCD[j][i] = GCD(table_GCD[j][i - 1],
                                      table_GCD[j + (1 << (i - 1))][i - 1]);
            }
        }
        table_max.resize(A.size());
        fill(table_max.begin(), table_max.end(),
             vector<long long>(log_table[A.size()] + 1));
        for(long long i = 0; i < A.size(); i++) table_max[i][0] = A[i];
        for(long long i = 1; (1 << i) <= A.size(); i++) {
            for(long long j = 0; j + (1 << i) <= A.size(); j++) {
                table_max[j][i] = max(table_max[j][i - 1],
                                      table_max[j + (1 << (i - 1))][i - 1]);
            }
        }
    }
    long long query_GCD(long long i, long long j) {
        return GCD(table_GCD[i][log_table[j - i + 1]],
                   table_GCD[j - (1 << log_table[j - i + 1]) + 1]
                            [log_table[j - i + 1]]);
    }
    long long query_max(long long i, long long j) {
        return max(table_max[i][log_table[j - i + 1]],
                   table_max[j - (1 << log_table[j - i + 1]) + 1]
                            [log_table[j - i + 1]]);
    }
};

/* main */

signed main() {
    ll N;
    cin >> N;
    vl A(N);
    FOR(i, 0, N) cin >> A[i];
    ll ans = 0;
    SparseTable st(A);
    ans = max(ans, st.query_GCD(1, N-1));
    ans = max(ans, st.query_GCD(0, N-2));
    FOR(i, 1, N - 1) {
        ll tmp = GCD(st.query_GCD(0, i - 1), st.query_GCD(i + 1, N - 1));
        ans = max(ans, tmp);
    }
    cout << ans << endl;
}

Measured memory_bytes: 34688