#include <iostream>

#include <algorithm>

#include <vector>

using namespace std;

typedef long long LL;

const int NICO = 100000 + 10;

int n; vector<int> v;

LL a[NICO], pre[NICO], suf[NICO];

LL gcd(LL x, LL y)

{

    return (y==0)?x:gcd(y, x%y);

}

int main()

{

    scanf("%d", &n);

    for(int i=1;i<=n;i++)

    {

        cin >> a[i];

    }

    if(n == 1)

    {

        cout << (LL)2e18 << endl;

    } else {

        int pos = 0;

        pre[1] = a[1]; suf[n] = a[n];

        for(int i=2;i<=n;i++)

        {

            pre[i] = gcd(a[i], pre[i-1]);

        }

        for(int i=n-1;i>=1;i--)

        {

            suf[i] = gcd(a[i], suf[i+1]);

        }

        for(int i=2;i<=n-1;i++)

        {

            LL tmp = gcd(pre[i-1],suf[i+1]);

            if(a[i] % tmp)

            {

                pos = i;

            }

        }

        if(a[1] % suf[2])   pos = 1;

        if(a[n] % pre[n-1]) pos = n;

        // pos 表示光头出现的位置

        if(pos==1) swap(a[1], a[2]), pos = 2;

        LL res = a[1];

        for(int i=2;i<=n;i++)

        {

            if(i!=pos) res = gcd(res, a[i]); // 碰见光头就跳过！

        }

        cout << res << endl;

    }

}