#include<bits/stdc++.h>
#define int long long
using namespace std;
int n,a[1000001],ans;
int dist(int i,int j){
	return min(abs(i-j),n-abs(i-j));
}
bool cmp(int a,int b){
	return a>b;
}
signed main(){
	freopen("transportt.in","r",stdin);
	freopen("transportt.out","w",stdout);
	cin>>n;
	for(int i=1;i<=n;i++){
		cin>>a[i];
	}
	sort(a+1,a+1+n,cmp); 
	for(int i=1;i<=min(5000LL,n);i++){
		for(int j=i+1;j<=min(5000LL,n);j++){
			ans=max(ans,a[i]+a[j]+dist(i,j));
		}
	}
	cout<<ans;
}