#include <bits/stdc++.h>

#define FOR(i,a,b) for(int i= (a); i<((int)b); ++i)
#define RFOR(i,a) for(int i=(a); i >= 0; --i)
#define FOE(i,a) for(auto i : a)
#define ALL(c) (c).begin(), (c).end()
#define RALL(c) (c).rbegin(), (c).rend()
#define DUMP(x)  cerr << #x << " = " << (x) << endl;
#define SUM(x) std::accumulate(ALL(x), 0LL)
#define MIN(v) *std::min_element(v.begin(), v.end())
#define MAX(v) *std::max_element(v.begin(), v.end())
#define EXIST(v,x) (std::find(v.begin(), v.end(), x) != v.end())
#define BIT_ON(bit, i) (bit & (1LL << i))

typedef long long LL;
template<typename T> using V = std::vector<T>;
template<typename T> using VV = std::vector<std::vector<T>>;
template<typename T> using VVV = std::vector<std::vector<std::vector<T>>>;
template<typename T> using VVVV = std::vector<std::vector<std::vector<std::vector<T>>>>;

template<class T> inline T ceil(T a, T b) { return (a + b - 1) / b; }
template<class T> inline void print(T x) { std::cout << x << std::endl; }
template<class T> inline void print_vec(const std::vector<T> &v) { for (int i = 0; i < v.size(); ++i) {  if (i != 0) {std::cout << " ";} std::cout << v[i];} std::cout << "\n"; }
template<class T> inline bool inside(T y, T x, T H, T W) {return 0 <= y and y < H and 0 <= x and x < W; }
template<class T> inline double euclidean_distance(T y1, T x1, T y2, T x2) { return sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2)); }
template<class T> inline double manhattan_distance(T y1, T x1, T y2, T x2) { return abs(x1 - x2) + abs(y1 - y2); }
template<class T> inline std::vector<T> unique(std::vector<T> v) {
    sort(v.begin(), v.end());
    v.erase(unique(v.begin(), v.end()), v.end());
    return v;
}

const int INF = 1 << 30;
const double EPS = 1e-9;
const std::string YES = "YES", Yes = "Yes", NO = "NO", No = "No";
const std::vector<int> dy4 = { 0, 1, 0, -1 }, dx4 = { 1, 0, -1, 0 };    // 4近傍（右, 下, 左, 上）
const std::vector<int> dy8 = { 0, -1, 0, 1, 1, -1, -1, 1 }, dx8 = { 1, 0, -1, 0, 1, 1, -1, -1 };

using namespace std;


LL func(int no, int left, int right, VV<LL> &dp, const V<LL> &A) {
    int N = A.size();
    if (dp[left][right] != -1) {
        return dp[left][right];
    }

    if (no == N) {
        return 0;
    }

    if (no % 2 == 0) {
        LL ans = 0;
        // leftをとる
        ans = max(ans, func(no + 1, (left + 1) % N, right, dp, A) + A[left]);
        // rightをとる
        ans = max(ans, func(no + 1, left, (right - 1 + N) % N, dp, A) + A[right]);

        return dp[left][right] = ans;
    }
    else {
        if (A[left] < A[right]) {
            return dp[left][right] = func(no + 1, left, (right - 1 + N) % N, dp, A);
        }
        else {
            return dp[left][right] = func(no + 1, (left + 1) % N, right, dp, A);
        }
    }
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    int N;
    cin >> N;
    V<LL> A(N);
    FOR(i, 0, N) {
        cin >> A[i];
    }

    if (N == 1) {
        print(A[0]);
        return 0;
    }
    if (N == 2) {
        print(max(A[0], A[1]));
        return 0;
    }

    LL ans = 0;
    VV<LL> dp(N, V<LL>(N, -1));
    FOR(i, 0, N) {
        int left = (i + 1) % N;
        int right = (i - 1 + N) % N;

        ans = max(ans, func(1, left, right, dp, A) + A[i]);
    }
    print(ans);

    return 0;
}


Measured memory_bytes: 34620