#include <bits/stdc++.h>
using namespace std;

#define NDEBUG
#include <cassert>


typedef long long ll;
typedef long double Double;
typedef unsigned long long ull;
typedef pair<int,int> ii;
typedef pair<ll,ll> llll;
typedef pair<double,double> dd;

typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef vector<ii> vii;
typedef vector<vector<ii>> vvii;
typedef vector<ll> vll;
typedef vector<string> vs;
typedef vector<double> vd;
typedef vector<long double> vD;

#define sz(a)  int((a).size())
#define pb  push_back
#define eb  emplace_back
#define FOR(var,from,to) for(int var=(from);var<=(to);++var)
#define rep(var,n)  for(int var=0;var<(n);++var)
#define rep1(var,n)  for(int var=1;var<=(n);++var)
#define repC2(vari,varj,n)  for(int vari=0;vari<(n)-1;++vari)for(int varj=vari+1;varj<(n);++varj)
#define ALL(c)  (c).begin(),(c).end()
#define RALL(c)  (c).rbegin(),(c).rend()
#define tr(i,c)  for(auto i=(c).begin(); i!=(c).end(); ++i)
#define found(s,e)  ((s).find(e)!=(s).end())
#define mset(arr,val)  memset(arr,val,sizeof(arr))
#define mid(x,y) ((x)+((y)-(x))/2)
#define IN(x,a,b) ((a)<=(x)&&(x)<=(b))
#define cons make_pair

#define PQ(T) priority_queue<T>
#define RPQ(T) priority_queue<T,vector<T>,greater<T>>

template<class T> inline void amin(T & a, T const & b) { a = min(a, b); }
template<class T> inline void amax(T & a, T const & b) { a = max(a, b); }

inline ll square(ll x) { return x * x; }
inline int gcd(int a, int b) { while(a) swap(a, b%=a); return b; }


#define INTSPACE 12
char _buf[INTSPACE*1000000 + 3];

int loadint() {
    if (fgets(_buf, INTSPACE+3, stdin)==NULL) return 0;
    return atoi(_buf);
}

int loadvec(vector<int>& v, int N=-1) {
    if (N == 0) {
        v.clear();
        return 0;
    }
    if (N == -1) {
        N = loadint();
        if (N==0) return 0;
    }
    int bufsize = INTSPACE*N + 3;
    if (fgets(_buf, bufsize, stdin)==NULL) return 0;
    v.resize(N);

    int i=0;
    bool last = false;
    for (char *p=&_buf[0]; ;) {
        char *q = p;
        while (*q > ' ') ++q;
        if (*q == 0x0D || *q == 0x0A) last = true;
        *q = 0;
        v[i++] = atoi(p);
        if (last || i == N) break;
        p = q+1;
    }
    return i;
}
void read_cr() {
    fgets(_buf, 256, stdin);
}


template <typename T>
class SegmentTree {
public:
    int bit_, N;
    vector<T> buf_;
    using MERGER = function<T(T,T)>;
    MERGER merge;
    T ident;

    SegmentTree(int size, MERGER merge, T ident) : merge(merge), ident(ident) {
        N = 1;
        bit_ = 0;
        while (N < size) {
            N *= 2;
            ++bit_;
        }
        buf_.assign(N*2, ident);
    }

    void update(int i, T x) {
        i = N + i - 1;

        if (merge(buf_[i], x) != x) return;

        buf_[i] = x;
        while (i > 0) {
			i = (i - 1) / 2;
			buf_[i] = merge(buf_[i*2+1], buf_[i*2+2]);
        }
    }

    T query(int lo, int hi) {
        return query(lo, hi, 0, 0, N);
    }
    T query(int a, int b, int k, int l, int r) {
        if (r <= a || b <= l) return ident;

        if (a <= l && r <= b) {
            return buf_[k];
        } else {
			T lv = query(a, b, 2*k+1, l, (l+r)/2);
			T rb = query(a, b, 2*k+2, (l+r)/2, r);
			return merge(lv, rb);
        }
    }

    void dump() {
    }
};

template <typename T>
class GcdSegmentTree : public SegmentTree<T> {
 public:
    GcdSegmentTree(int size) :
        SegmentTree<T>(size,
                       [](T a,T b){return gcd(a,b);},
                       0) {}
};

int solve(int N, vi& a) {
    GcdSegmentTree<int> st(N);
    rep(i,N) st.update(i, a[i]);

    int best = 0;
    rep(i,N) {
        int g = gcd(st.query(0,i), st.query(i+1,N));
        amax(best, g);
    }
    return best;
}

int main() {
    vi a;
    int N = loadvec(a);
    cout << solve(N,a) << endl;
    return 0;
}


Measured memory_bytes: 2688