using static System.Math;
using static System.Console;
using System.Collections.Generic;
using System.Linq;
using System;
using System.Runtime.CompilerServices;

class Program
{
    #region Reader
    static string ReadStr => Console.ReadLine();
    static string[] ReadStrs => Console.ReadLine().Split(' ');
    static int ReadInt => Convert.ToInt32(Console.ReadLine().Trim());
    static int[] ReadInts => Console.ReadLine().Trim().Split(' ').Select(s => Convert.ToInt32(s)).ToArray();
    static long ReadLong => Convert.ToInt64(Console.ReadLine().Trim());
    static long[] ReadLongs => Console.ReadLine().Trim().Split(' ').Select(s => Convert.ToInt64(s)).ToArray();
    static List<int[]> ReadPairs(int N)
    {
        List<int[]> ans = new List<int[]>();
        for (int i = 0; i < N; i++) { ans.Add(ReadInts); }
        return ans;
    }
    static List<long[]> ReadPairsLong(int N)
    {
        List<long[]> ans = new List<long[]>();
        for (int i = 0; i < N; i++) { ans.Add(ReadLongs); }
        return ans;
    }
    #endregion
    #region Method
    const int mod = 1000000007;
    public static int Mod(int a, int mod) { return a % mod >= 0 ? a % mod : a % mod + mod; }
    public static long Mod(long a, long mod = mod) { return a % mod >= 0 ? a % mod : a % mod + mod; }
    bool eq<T, U>() => typeof(T).Equals(typeof(U));
    T ct<T, U>(U a) => (T)Convert.ChangeType(a, typeof(T));
    T cv<T>(string s) => eq<T, int>() ? ct<T, int>(int.Parse(s))
                       : eq<T, long>() ? ct<T, long>(long.Parse(s))
                       : eq<T, double>() ? ct<T, double>(double.Parse(s))
                       : eq<T, char>() ? ct<T, char>(s[0])
                                         : ct<T, string>(s);
    void Multi<T>(out T a) => a = cv<T>(ReadStr);
    void Multi<T, U>(out (T,U) ans)
    {
        var ar = ReadStrs;
        ans =(cv<T>(ar[0]), cv<U>(ar[1]));
    }
    void Multi<T, U, V>(out (T,U,V) ans)
    {
        var ar = ReadStrs; 
        ans =(cv<T>(ar[0]), cv<U>(ar[1]),cv<V>(ar[2]));
    }
    void Multi<T,U>(out T a,out U b)
    {
        var ar = ReadStrs; 
        a = cv<T>(ar[0]);  b = cv<U>(ar[1]);
    }
    void Multi<T, U, V>(out T a,out U b,out V c)
    {
        var ar = ReadStrs;
        a = cv<T>(ar[0]);  b = cv<U>(ar[1]);  c = cv<V>(ar[2]);
    }
    #endregion


    static void Main()
    {
        int N = ReadInt;

        int[] As = ReadInts;

        long[] right = new long[N];
        long[] left = new long[N];

        right[0] = As[0];
        left[N-1] = As[N-1];

        for (int i = 1; i < N; i++)
        {
            right[i] = Gcd(right[i - 1], As[i]);

            left[N-i-1] = Gcd(left[N-i], As[N - i - 1]);
        }

        long ans = Max(right[N-2],left[1]);

        for (int i = 0; i < N-2; i++)
        {
            ans = Max(ans, Gcd(right[i], left[i + 2]));
        }

        WriteLine(ans);
    }

    /// <summary>
    /// 最大公約数
    /// </summary>
    /// <param name="a"></param>
    /// <param name="b"></param>
    /// <returns></returns>
    public static long Gcd(long a, long b)
    {
        if (a < b)
            // 引数を入替えて自分を呼び出す
            return Gcd(b, a);
        while (b != 0)
        {
            var remainder = a % b;
            a = b;
            b = remainder;
        }
        return a;
    }

}



Measured memory_bytes: 39764