#include<bits/stdc++.h>
using namespace std;
#define rc(x) return cout<<x<<endl,0
#define pb push_back
#define dbg(x) cout << #x << '=' << x << '\n';
#define ll long long
#define sz size()
#define x first
#define y second
#define pi pair <int, int>
#define pii pair <int, pi>
#define vi vector <int>
const ll mod = 1e9 + 7;
int n, a[500001], s[1000001];
int32_t main(){
ios_base :: sync_with_stdio(0); cin.tie(); cout.tie();
cin>>n;
for(int i=0; i<n; i++){
cin>>a[i];
if(i) s[i]=s[i-1]+a[i];
else s[i]=a[i];
}
for(int i=n; i<=2*n; i++) s[i]=s[i-1]+a[i%n];
//for(int i=0; i<=2*n; i++) cout<<i<<" "<<s[i]<<endl;
int ans=0;
for(int i=0; i<n; i++){
int cur=0;
for(int j=i+1; j<=(n+1)/2+i; j++) cur=max(cur, s[j+n/2]-s[j]);
ans=max(ans, s[n-1]-cur);
}
cout<<ans;
}
