// compile: make data
// run: ./data < data.in
#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#ifdef LOCAL
#include <debug/codeforces.h>
#define debug(x...) _debug_print(#x, x);
#define Debug(x...) _debug_print_format(#x, x);
std::ifstream terminal("/dev/tty");
#define PP cerr<<"\033[1;30mpause...\e[0m",terminal.ignore();
#else
#define debug(x...)
#define Debug(x...)
#define PP
#endif
template<typename...Args> void print_(Args...args){((cout<<args<<" "),...)<<endl;}
#define VI vector<int>
#define VII vector<vector<int>>
#define VIII vector<vector<vector<int>>>
#define rep(i,a,b) for(int i=(a);i<(int)(b);++i)
#define sz(v) ((int)(v).size())
#define print(...) print_(__VA_ARGS__);
#define FIND(a, x) ((find(a.begin(),a.end(),(x))!=a.end())?1:0)
#define cmin(x,...) x=min({(x), __VA_ARGS__})
#define cmax(x,...) x=max({(x), __VA_ARGS__})
#define INTMAX (int)(9223372036854775807)
#define INF (int)(1152921504606846976)
#define NaN (int)(0x8b88e1d0595d51d1)
#define double long double
#define int long long
#define uint unsigned long long
#define MAXN 200010

int32_t main() {
    ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);

    int n; cin >> n;
    vector<int> a(n);
    rep(i, 0, n) cin >> a[i];
    vector<vector<int>> dp(n, vector<int>(n, -1));
    function<int(int, int)> dfs = [&](int l, int r) -> int {
        if (l > r) return 0;
        if (~dp[l][r]) return dp[l][r];
        if (l == r) {
            dp[l][r] = a[l];
            return a[l];
        }
        int opl = a[l] + min(dfs(l + 2, r), dfs(l + 1, r - 1));
        int opr = a[r] + min(dfs(l + 1, r - 1), dfs(l, r - 2));
        return dp[l][r] = max(opl, opr);
    };
    int ans = dfs(0, n-1);
    cout << ans << endl;

    return 0;
}