#include <bits/stdc++.h>
#define ld long double
#define endl "\n"
#define fastio ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define pb(x) push_back(x)
#define mp(a,b) make_pair(a,b)
#define ms(v,x) memset(v,x,sizeof(v))
#define all(v) v.begin(),v.end()
#define ff first
#define ss second
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define per(i, a, b) for(int i = b-1; i>=a ; i--)
#define trav(a, x) for(auto& a : x)
#define allin(a , x) for(auto a : x)
#define Unique(v) sort(all(v));v.erase(unique(all(v)),v.end());
#define sz(v) (int)v.size()
//#define int long long
using namespace std;
typedef vector<int> vi;
#define y1 abacaba
#define left sefude
#define db(x) cerr << #x <<" == "<<x << endl;
#define db2(x,y) cerr<<#x <<" == "<<x<<", "<<#y<<" == "<<y<<endl;
#define db3(x,y,z) cerr << #x<<" == "<<x<<", "<<#y<<" == "<<y<<", "<<#z<<" == "<<z<<endl;
#define prl cerr<<"called: "<< __LINE__<<endl;
typedef long long ll;
typedef pair<int,int> pii;
inline ll mod(ll n, ll m ){ ll ret = n%m; if(ret < 0) ret += m; return ret; }
ll gcd(ll a, ll b){return (b == 0LL ? a : gcd(b, a%b));}
ll exp(ll a,ll b,ll m){
if(b==0LL) return 1LL;
if(b==1LL) return mod(a,m);
ll k = mod(exp(a,b/2,m),m);
if(b&1LL){
return mod(a*mod(k*k,m),m);
}
else return mod(k*k,m);
}
const int N = 5050 * 3;
int a[N];
int pre[N];
int32_t main(){
fastio;
int n;
cin>>n;
for(int i=1;i<=n;i++){
cin >> a[i];
a[i+n] = a[i+n*2] = a[i];
}
for(int i=1;i<=3*n;i++){
pre[i] = pre[i-1] + a[i];
}
int res=0;
int tam = (n+1)/2;
for(int i=n+1;i<=2*n;i++){
int best = 1e9 + 7;
for(int k=0;k<tam;k++){
best = min(best,pre[i + k] - pre[i - (tam - k)]);
}
res = max(res,best);
}
cout << res << endl;
// menor subarray de tamanho (n+1)/2 que contém POS
// math -> gcd it all
// Did u check N=1? Did you switch N,M?
}
