#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <climits>
#include <iostream>
#include <vector>
#include <string>
#include <sstream>
#include <algorithm>
#include <utility>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <deque>
#include <functional>

using namespace std;

#define fst first
#define scd second
#define PB push_back
#define MP make_pair
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define omajinai ios::sync_with_stdio(false);cin.tie(0)
#define rep(i,x) for(int i=0;i<(int)(x);++i)
#define rep1(i,x) for(int i=1;i<=(int)(x);++i)

typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> pii;
typedef vector<pii> vpii;

template<typename T>T& max(T&a,T&b){if(a>=b)return a;return b;}
template<typename T>T& min(T&a,T&b){if(a<b)return a;return b;}
template<typename T>bool chmax(T&a,T b){if(a<b){a=b;return true;}return false;}
template<typename T>bool chmin(T&a,T b){if(a>b){a=b;return true;}return false;}
template<typename T>T get(){T a;cin>>a;return a;}
template<typename T>T rev(T a){reverse(all(a));return a;}
template<typename T>vector<T>&sort(vector<T>&a){sort(all(a));return a;}

const int inf = 1e9;
const ll linf = 3e18;
const double eps = 1e-9;

ll N;
ll A[2005];

ll dp[2010][2010][2]; // dp[??????][??????][?????????]

ll conv(int pos)
{
    if (pos < 0) return N - 1;
    if (pos >= N) return 0;
    return pos;
}

ll rec(ll l, ll r, bool turn)
{
    if (l == r) return A[l] * !turn;
    
    if (~dp[l][r][turn]) return dp[l][r][turn];

    ll res = 0;

    if (turn == false) { // JOI
        res = max(A[l] + rec(conv(l - 1), r, turn ^ 1), A[r] + rec(l, conv(r + 1), turn ^ 1));
    } else {
        if (A[l] > A[r]) {
            res = rec(conv(l - 1), r, turn ^ 1);
        } else {
            res = rec(l, conv(r + 1), turn ^ 1);
        }
    }

    return dp[l][r][turn] = res;
}

signed main()
{
    memset(dp, -1, sizeof(dp));
    cin >> N;

    rep(i, N) {
        cin >> A[i];
    }

    ll ma = 0;

    rep(i, N) {
        ma = max(ma, A[i] + rec(conv(i - 1), conv(i + 1), 1));
    }

    cout << ma << endl;
}