#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ar array
const int mxN=5e5;
int n, a[2*mxN], p[2*mxN+1], val[2*mxN+1];
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cin >> n;
for (int i=0; i<n; ++i) {
cin >> a[i];
a[i+n]=a[i];
}
for (int i=0; i<2*n; ++i)
p[i+1]=p[i]+a[i];
for (int i=1; i+n/2<=2*n; ++i)
val[i]=p[i+n/2]-p[i];
int ans=0;
/*for (int rep=0; rep<n; ++rep) {
for (int i=0; i<n; ++i)
p[i+1]=p[i]+a[i];
int mx=0;
for (int j=1; j+n/2-1<n; ++j)
mx=max(mx, p[j+n/2]-p[j]);
ans=max(ans, p[n]-mx);
rotate(a, a+1, a+n);
}*/
for (int i=0; i<n; ++i) {
int mx=0;
for (int j=1; j<=(n+1)/2; ++j)
mx=max(mx, val[i+j]);
ans=max(ans, p[n]-mx);
}
cout << ans;
return 0;
}
