#include<bits/stdc++.h>
using namespace std;
const int MAX_N = 12 * 500'000;
int ST[MAX_N];
int N, NN;
int get_min(int l, int r){
l += NN, r += NN;
int res = int(1e9);
while(l <= r){
if(l % 2 == 1) res = min(res, ST[l++]);
if(r % 2 == 0) res = min(res, ST[r--]);
l /= 2, r /= 2;
}
return res;
}
void SET(int pos, int val){
pos += NN;
ST[pos] = val;
for(pos /= 2;pos >= 1;pos /= 2) ST[pos] = min(ST[2 * pos], ST[2 * pos + 1]);
}
int main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
for(int i = 0;i < MAX_N;i++) ST[i] = (int)1e9;
cin >> N;
NN = 3 * N;
vector<int> A(N);
for(int &x : A) cin >> x; // A[i] <= 2000
for(int i = 0;i < N;i++) A.push_back(A[i]);
for(int i = 0;i < N;i++) A.push_back(A[i]);
vector<array<int, 3>> wids;
auto add = [&](int s, int l, int r)->void{
wids.push_back({s, l, r});
};
int K = (N + 1) / 2;
int sum = 0;
for(int i = 0;i < K;i++){
sum += A[N-K+i+1];
}
add(sum, N-K+1, N);
for(int i = N + 1;i < 3 * N;++i){
sum += A[i];
sum -= A[i - K];
add(sum, i - K + 1, i);
}
vector<int> in(NN, -1), out(NN, -1);
vector<int> sums;
int id = 0;
for(auto [s, l, r] : wids){
sums.push_back(s);
swap(l, r);
if(in[l] == -1) in[l] = id;
if(out[r] == -1 && in[r] != -1) out[r] = id;
++id;
}
int ans = 0;
for(int i = 0;i < (int)sums.size();i++){
SET(i, sums[i]);
}
for(int i = 0;i < NN;i++){
if(in[i] == -1 || out[i] == -1) continue;
//~ for(int j = in[i];j <= out[i];j++) res = min(res, sums[j]);
ans = max(ans, get_min(in[i], out[i]));
}
cout << ans << '\n';
return 0;
}
