#include <iostream>
using namespace std;
int nums[500000];
//int sums[500000];
// 0 to 8388606 for root/internal
// 8388607 + x for leaves
int sums[16777215];
int n, k;
int getItem(int i){
return nums[i%n];
}
int query(int l, int r, int i = 0, int x = 0, int y =8388607){
if (l==x&&y==r){
return sums[i];
}
int result= 1000000001;
int mid = (x+y+1)/2;
if (l < mid){
result = min (result, query(l, min(r, mid-1), 2*i+1, x, mid-1));
}
if (r >= mid){
result = min(result, query(max(l, mid), r, 2*i+2, mid, y));
}
return result;
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
cin >> n;
for (int i = 0; i < n; i++){
cin >> nums[i];
}
// Bytesar gets worst set of adjacent n/2 + n%2
k = n/2 + n%2;
sums[0+8388607]=0;
// sums starting at i, up to i + k-1
for (int i = 0; i < k; i++){
sums[0+8388607] += nums[i];
}
for (int i = 1; i < n; i++){
sums[i+8388607] = sums[i-1+8388607];
sums[i+8388607] += getItem(i+k-1) - getItem(i-1);
//cout << sums[i+8388607] << endl;
}
for (int i = 8388606; i>=0; i--){
sums[i] = min(sums[2*i+1], sums[2*i+2]);
}
int best = 0;
for (int i = 0; i < n; i++){
// starts can be anywher from i-k+1, to i;
int start = i-k+1;
int last= i, minimum;
if (start < 0){
minimum = min(
query((start+n)%n, n-1),
query(0, last)
);
}
else{
minimum = query(start, last);
}
best = max(best, minimum);
}
cout << best << '\n';
}
