#include <bits/stdc++.h>
#define ll long long
#define s second
#define f first
#define pb push_back
#define left (h*2),l,(l + r)/2
#define right (h*2+1),(l+r)/2 + 1,r
#define pii pair <int,int>
#define int ll
using namespace std;
const int N = 1e6 + 5,inf = 1e18;
int lz[4*N],t[4*N],p[N],a[N];
void build(int h,int l,int r){
t[h] = inf;
if (l == r) return;
build(left);
build(right);
}
void upd(int h,int l,int r,int L,int R,int vl){
if (r < L || R < l) return ;
if (L <= l && r <= R) {
t[h] = min(t[h],vl);
return;
}
upd(left,L,R,vl);
upd(right,L,R,vl);
}
int get(int h,int l,int r,int idx){
if (l == r) return t[h];
if (idx > (l + r)/2) return min(t[h],get(right,idx));
return min(t[h],get(left,idx));
}
signed main(){
ios_base::sync_with_stdio(0),cin.tie(NULL),cout.tie(NULL);
int n;
cin>>n;
for (int i =1; i <= n; i++){
cin >> a[i];
p[i] = p[i - 1] + a[i];
}
for (int i = n + 1; i <= 2*n; i++)
a[i] = a[i - n],p[i] = p[i - 1] + a[i];
build(1,1,2*n);
int len = (n + 1)/2;
for (int i = 1; i <= n; i++)
upd(1,1,2*n,i, i + len - 1,p[i + len - 1] - p[i - 1]);
int ans = 0;
for (int i = n + 1; i <= 2*n; i++)
ans = max(ans,min(get(1,1,2*n,i),get(1,1,2*n,i - n)));
cout<<ans;
}
