import core.bitop;
import std.algorithm;
import std.ascii;
import std.bigint;
import std.conv;
import std.functional;
import std.format;
import std.math;
import std.numeric;
import std.range;
import std.stdio;
import std.string;
import std.random;
import std.typecons;

alias sread = () => readln.chomp();
alias Point2 = Tuple!(long, "y", long, "x");

T lread(T = long)()
{
    return readln.chomp.to!T();
}

T[] aryread(T = long)()
{
    return readln.split.to!(T[])();
}

void scan(TList...)(ref TList Args)
{
    auto line = readln.split();
    foreach (i, T; TList)
    {
        T val = line[i].to!(T);
        Args[i] = val;
    }
}


//右側と左側からのgcdをやると計算量が減るらしい．
void main()
{
    auto n = lread();
    auto a = aryread();
    long[] b = new long[n + 1];
    long[] c = new long[n + 1];
    foreach (i, ref e; b)
    {
        if (i == 0)
        {
            continue;
        }
        e = gcd(b[i - 1], a[i - 1]);
    }
    foreach_reverse (i, ref e; c)
    {
        if (i == n)
        {
            continue;
        }
        e = gcd(c[i + 1], a[i]);
    }
    // writeln(a);
    // writeln(b);
    // writeln(c);
    long max_gcd = 0;
    foreach (i; 0 .. n)
    {
        max_gcd = max(gcd(b[i], c[i + 1]), max_gcd);
    }
    writeln(max_gcd);
}