import std.algorithm, std.container, std.conv, std.math, std.range, std.typecons, std.stdio, std.string;
import std.numeric;

auto rdsp(){return readln.splitter;}
void pick(R,T)(ref R r,ref T t){t=r.front.to!T;r.popFront;}
void readV(T...)(ref T t){auto r=rdsp;foreach(ref v;t)pick(r,v);}
void readA(T)(size_t n,ref T[]t){t=new T[](n);auto r=rdsp;foreach(ref v;t)pick(r,v);}

void main()
{
  int n; readV(n);
  int[] a; readA(n, a);

  auto b = new int[](n); b[0] = a[0];
  foreach (i; 1..n) b[i] = gcd(b[i-1], a[i]);
  auto c = new int[](n); c[$-1] = a[$-1];
  foreach_reverse (i; 0..n-1) c[i] = gcd(c[i+1], a[i]);

  auto r = max(b[$-2], c[1]);
  foreach (i; 1..n-1)
    r = max(r, gcd(b[i-1], c[i+1]));

  writeln(r);
}
