using System;
using System.Collections.Generic;
using System.Collections;
using System.Collections.Specialized;
using System.Linq;
using System.Text;
using System.IO;
using System.Reflection;
using static System.Math;
using System.Numerics;
static class Program{
	const int mod=(int)1e9+7;
	static void Main(){
		Sc sc=new Sc();
		var n=sc.I;
		var a=sc.Ia;
		St st=new St(a,true);
		long ans=0;
		for(int i = 0;i<n;i++) {
			ans=Max(ans,Gcd(st.Get(0,i-1).d,st.Get(i+1,n).d));
		}
		Console.WriteLine("{0}",ans);
	}
	static long Gcd(long a,long b){
		if(a==0||b==0){return a>b?a:b;}
		long c=Max(a,b)%(b=Min(a,b));
		while(c!=0){
			a=b%c;
			b=c;
			c=a;
		}
		return b;
	}
}
public struct Dt{
	public long d;
	public Dt(bool b){d=b?0:0;}
	public Dt(long d){this.d=d;}
	public static Dt Cm(Dt a,Dt b){
		if(a.d==0||b.d==0){return a.d>b.d?a:b;}
		long e=a.d,d=Min(a.d,b.d);
		long c=Max(a.d,b.d)%d;
		while(c!=0){
			e=d%c;
			d=c;
			c=e;
		}
		return new Dt(d);
	}
	public static bool operator==(Dt a,Dt b){return a.d==b.d;}
	public static bool operator!=(Dt a,Dt b){return a.d!=b.d;}
	public override bool Equals(object obj){return false;}
	public override int GetHashCode(){return 0;}
}
public class St{
	public Dt[] dat;
	private int m=1;
	private bool ku;
	private Dt du;
	public St(int n,bool ku){
		this.ku=ku;
		du=new Dt(false);
		while(m<n){m<<=1;}
		m--;
		dat=new Dt[m+n+1];
		dat[m+n]=du;
		for(int i=m+n-1;i>=m;i--){dat[i]=new Dt(true);}
		for(int i=m-1;i>=0;i--){dat[i]=(i<<1)+1<m+n?dat[(i<<1)+1]:du;}
	}
	public St(int[] a,bool ku){
		this.ku=ku;
		int n=a.Length;
		du=new Dt(false);
		while(m<n){m<<=1;}
		m--;
		dat=new Dt[m+n+1];
		dat[m+n]=du;
		for(int i=m+n-1;i>=m;i--){dat[i]=new Dt(a[i-m]);}
		for(int i=m-1;i>=0;i--){
			if((i<<1)+2<m+n){dat[i]=Dt.Cm(dat[(i<<1)+1],dat[(i<<1)+2]);}
			else if((i<<1)+1<m+n){dat[i]=dat[(i<<1)+1];}
			else{dat[i]=du;}
		}
	}
	public void Ud(int q,long b){
		q+=m;
		dat[q].d=ku?dat[q].d+b:b;
		q=(q-1)>>1;
		while(q>=0){
			Dt o=Dt.Cm(dat[(q<<1)+1],dat[(q<<1)+2]);
			if(dat[q]==o){break;}
			dat[q]=o;
			q=(q-1)>>1;
		}
	}
	private Dt Fdg(int a,int b,int k,int l,int r){
		if(r<a||b<l){return du;}
		if(a<=l&&r<=b){return dat[k];}
		Dt p=Fdg(a,b,k*2+1,l,(l+r)>>1);
		Dt q=Fdg(a,b,k*2+2,(l+r+1)>>1,r);
		return Dt.Cm(p,q);
	}
	public Dt Get(int a,int b){return a>b?du:Fdg(a,b,0,0,m);}
}
public class Sc{
	public int I{get{return int.Parse(Console.ReadLine());}}
	public long L{get{return long.Parse(Console.ReadLine());}}
	public double D{get{return double.Parse(Console.ReadLine());}}
	public string S{get{return Console.ReadLine();}}
	public int[] Ia{get{return Array.ConvertAll(Console.ReadLine().Split(),int.Parse);}}
	public long[] La{get{return Array.ConvertAll(Console.ReadLine().Split(),long.Parse);}}
	public double[] Da{get{return Array.ConvertAll(Console.ReadLine().Split(),double.Parse);}}
	public string[] Sa{get{return Console.ReadLine().Split();}}
	public object[] Oa{get{return Console.ReadLine().Split();}}
	public int[] Ia2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),int.Parse);}}
	public int[] Ia3(int a){return Array.ConvertAll((a.ToString()+" "+Console.ReadLine()).Split(),int.Parse);}
	public int[] Ia3(bool a,int b,bool c,int d){return Array.ConvertAll(((a?b.ToString()+" ":"")+Console.ReadLine()+(c?" "+d.ToString():"")).Split(),int.Parse);}
	public long[] La2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),long.Parse);}}
	public long[] La3(int a){return Array.ConvertAll((a.ToString()+" "+Console.ReadLine()).Split(),long.Parse);}
	public long[] La3(bool a,int b,bool c,int d){return Array.ConvertAll(((a?b.ToString()+" ":"")+Console.ReadLine()+(c?" "+d.ToString():"")).Split(),long.Parse);}
	public T[] Arr<T>(int n,Func<T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f();}return a;}
	public T[] Arr<T>(int n,Func<int,T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i);}return a;}
	public T[] Arr<T>(int n,Func<string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(Console.ReadLine().Split());}return a;}
	public T[] Arr<T>(int n,Func<int,string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i,Console.ReadLine().Split());}return a;}
}

Measured memory_bytes: 28892