#include<cstdio>

 #include<cstring>

 #include<algorithm>

 #include<cmath>

 #define LL long long

 #define rg register

 #define N 1000010

 using namespace std;

 int n,m,ans,a[N];

 bool p[N];

 inline int read(){

     int k=,f=; char c=getchar();

     while(c<''||c>'')c=='-'&&(f=-),c=getchar();

     while(''<=c&&c<='')k=k*+c-'',c=getchar();

     return k*f;

 }

 inline bool check(int x){

     int last=,now=x;

     while(now<=n){

         bool ok=;

         for(rg int i=last;i<=now;i++) ok=ok|p[i];

         if(!ok) return ;

         now+=x; last+=x;

     }

     return ;

 }

 int main(){

     n=read(); m=trunc(sqrt(n));

     for(rg int i=;i<=n;i++) a[i]=read();

     for(rg int i=;i<n;i++) if(a[i-]<a[i]&&a[i]>a[i+]) p[i]=;

     for(rg int i=;i<=m;i++)if(n%i==){

         if(check(i)) ans=max(ans,n/i);

         if(check(n/i)) ans=max(ans,i);

     }

     printf("%d\n",ans);

     return ;

 }