#include <bits/stdc++.h>
using namespace std;
const int mxn=5e5+5;
int n,a[mxn],b[mxn],ans=1e9,num=0;
struct segment{
int val[(1<<22)];
void build(int id,int L,int R){
if(L+1==R){
val[id]=b[L];
return;
}
int mid=(L+R)/2;
build(id*2,L,mid);
build(id*2+1,mid,R);
val[id]=max(val[id*2],val[id*2+1]);
}
int get(int id,int L,int R,int l,int r){
if(l==L && R==r)
return val[id];
int mid=(L+R)/2,res=0;
if(l<mid)
res=max(res,get(id*2,L,mid,l,min(r,mid)) );
if(r>mid)
res=max(res,get(id*2+1,mid,R,max(l,mid),r) );
return res;
}
}seg;
int main(){
cin>>n;
for(int i=0;i<n;i++){
cin>>a[i];
num+=a[i];
}
int sum=0;
for(int i=0;i<n/2;i++)
sum+=a[i];
for(int i=0;i<n;i++){
b[i]=sum;
sum-=a[i];
sum+=a[(i+n/2)%n];
//cout<<b[i]<<" ";
}
seg.build(1,0,n);
for(int i=0;i<n;i++){
int l=(i+1)%n,r=(i-n/2+n)%n,res=0;
//cout<<l<<" "<<r<<endl;
if(l<=r)
res=seg.get(1,0,n,l,r+1);
else
res=max(seg.get(1,0,n,l,n),seg.get(1,0,n,0,r+1));
ans=min(ans,res);
}
cout<<num-ans<<endl;
}
