#undef _GLIBCXX_DEBUG // disable run-time bound checking, etc
#pragma GCC optimize("Ofast,inline") // Ofast = O3,fast-math,allow-store-data-races,no-protect-parens
#pragma GCC optimize ("unroll-loops")
#pragma GCC target("bmi,bmi2,lzcnt,popcnt") // bit manipulation
#pragma GCC target("movbe") // byte swap
#pragma GCC target("aes,pclmul,rdrnd") // encryption
#pragma GCC target("avx,avx2,f16c,fma,sse3,ssse3,sse4.1,sse4.2") // SIMD
#include <bits/stdc++.h>
using namespace std;
#define enablell 1
typedef long long ll;
#if enablell
#define int ll
#define inf LLONG_MAX
#define float double
#else
#define inf int(2e9)
#endif
#define vi vector<int>
#define vvi vector<vi>
#define vvvi vector<vvi>
#define vvvvi vector<vvvi>
#define vb vector<bool>
#define vvb vector<vb>
#define vvvb vector<vvb>
#define p2 pair<int, int>
#define vp2 vector<p2>
#define vvp2 vector<vp2>
#define vvvp2 vector<vvp2>
#define p3 tuple<int,int,int>
#define vp3 vector<p3>
#define vvp3 vector<vp3>
#define vvvp3 vector<vvp3>
#define p4 tuple<int,int,int,int>
#define vp4 vector<p4>
//#define read(a) cin >> a
#define read2(a,b) cin >> a >> b
#define read3(a,b,c) cin >> a >> b >> c
//#define write(a) cout << (a) << "\n"
#define quit cout << endl; _Exit(0);
#define dread(type, a) type a; cin >> a
#define dread2(type, a, b) dread(type, a); dread(type, b)
#define dread3(type, a, b, c) dread2(type, a, b); dread(type, c)
#define dread4(type, a, b, c, d) dread3(type, a, b, c); dread(type, d)
#define dread5(type, a, b, c, d, e) dread4(type, a, b, c, d); dread(type, e)
#ifdef _DEBUG
#define noop cout << "";
#define deb __debugbreak();
#define debassert(expr) if (!(expr)) deb;
#define debif(expr) if(expr) deb;
#else
#define noop ;
#define deb ;
#define debassert(expr) ;
#define debif(expr) ;
#endif
#define rep(i, high) for (int i = 0; i < high; i++)
#define repp(i, low, high) for (int i = low; i < high; i++)
#define repe(i, container) for (auto& i : container)
#define per(i, high) for (int i = high-1; i >= 0; i--)
#define perr(i, low, high) for (int i = high-1; i >= low; i--)
#define readvector(type, name, size) vector<type> name(size); rep(i,size) {dread(type,temp); name[i]=temp;}
#define all(a) begin(a),end(a)
#define setcontains(set, x) (set.find(x) != set.end())
#define stringcontains(str, x) (str.find(x) != string::npos)
#define within(a, b, c, d) (a >= 0 && a < b && c >= 0 && c < d)
#define sz(container) ((int)container.size())
#define mp(a,b) (make_pair(a,b))
#define first(a) (*begin(a))
#define indexpair(p, i) ((i==0)?p.first:p.second)
#define chmax(a,b) ((a)=max((a),b))
#define chmin(a,b) ((a)=min((a),b))
#define ceildiv(x,y) ((x + y - 1) / y)
#define fract(a) (a-floor(a))
auto Start = chrono::high_resolution_clock::now();
#define elapsedmillis() (chrono::duration_cast<chrono::milliseconds>(chrono::high_resolution_clock::now() - Start).count())
#define rununtil(time) if (elapsedmillis() >= time) break;
inline void fast() { ios::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); }
template <typename T, typename U> inline void operator+=(std::pair<T, U>& l, const std::pair<T, U>& r) { l = { l.first + r.first,l.second + r.second }; }
template <typename T> inline int sgn(T val) { return (T(0) < val) - (val < T(0)); }
template <typename Out> inline void split(const string& s, char delim, Out result) { istringstream iss(s); string item; while (getline(iss, item, delim)) { *result++ = item; } }
inline vector<string> split(const string& s, char delim) { vector<string> elems; split(s, delim, back_inserter(elems)); return elems; }
inline int readintsigned() { int v = 0; int sign = 1; char c = getchar(); if (c == '-') { sign = -1; } else { v += c - '0'; } while ((c = getchar()) != EOF && c != ' ' && c != '\n') { v *= 10; v += c - '0'; } return v * sign; }
inline int readint() { int v = 0; char c; while ((c = getchar()) != EOF && c != ' ' && c != '\n') { v *= 10; v += c - '0'; } return v; }
inline string readstring() { string s; char c; while ((c = getchar()) != EOF && c != '\n' && c != ' ') { s.push_back(c); } return s; }
template<typename T> inline T gcd(T a, T b) { T c; while (b) { c = b; b = a % b; a = c; } return a; }
#define LOCAL _MSC_VER > 0
#if LOCAL
#define gc() getchar()
#else
#define gc() getchar_unlocked()
#if 0
#include <bits/extc++.h>
using namespace __gnu_pbds;
struct chash { // large odd number for C
const uint64_t C = ll(4e18 * acos(0)) | 71;
ll operator()(ll x) const { return x; }
};
typedef __gnu_pbds::gp_hash_table<int, null_type, chash> h;
#endif
#endif
struct Tree {
typedef int T;
static constexpr T unit = INT_MIN;
T f(T a, T b) { return max(a, b); } // (any associative fn)
vector<T> s; int n;
Tree(int n = 0, T def = unit) : s(2 * n, def), n(n) {}
void update(int pos, T val) {
for (s[pos += n] = val; pos /= 2;)
s[pos] = f(s[pos * 2], s[pos * 2 + 1]);
}
T query(int b, int e) { // query [b, e)
T ra = unit, rb = unit;
for (b += n, e += n; b < e; b /= 2, e /= 2) {
if (b % 2) ra = f(ra, s[b++]);
if (e % 2) rb = f(s[--e], rb);
}
return f(ra, rb);
}
};
int32_t main()
{
fast();
#if 0
//ifstream cin("C:\\Users\\Matis\\source\\repos\\Comp prog\\x64\\Debug\\in.txt");
//ifstream cin("C:\\Users\\Matis\\desktop\\po-two\\swedish-olympiad-2017\\onlinekval\\skidor\\testcases\\g3\\300rnd.in");
#endif
dread(int, n);
readvector(int, values, n);
int admintake = n / 2;
int v = 0;
repp(i, 0, admintake) v += values[i];
vi intervalsums(n);
int bestinterval = 0;
for (int i = 0; i < n; i++)
{
intervalsums[i] = v;
v -= values[i];
v += values[(i + admintake)%n];
}
vi prefix(n);
prefix[0] = values[0];
repp(i, 1, n) prefix[i] = prefix[i - 1] + values[i];
int sum = accumulate(all(values), 0LL);
vi best(n);
deque<int> q;
int len = n - admintake;
rep(i, n+ len -1)
{
while (q.size() && i- q.front() >= len) q.pop_front();
while (q.size() && intervalsums[q.back()%n] < intervalsums[i%n]) q.pop_back();
q.push_back(i);
if (i - len +1 >= 0) best[i - len +1] = intervalsums[q.front()%n];
}
int least = inf;
rep(i, n)
{
/* int upper = min(n, i + admintake);*/
least = min(least, best[i]);
}
cout << sum-least;
quit;
}
