#include <iostream>
#include <cstring>
using namespace std;
typedef long long ll;
int n;
int niza[5001];
ll dp[2][5001][5001];
ll rec(int turn, int start, int end){
    if(start==end){
        if(turn == 0) {
            return niza[start];
        }
        return 0;
    }

    if(dp[turn][start][end] != -1){
        return dp[turn][start][end];
    }

    ll result;

    if(turn==0){
        result = -1e18;
        result=max(result, rec(1, start+1, end)+niza[start]);
        result=max(result, rec(1, start, end-1)+niza[end]);
    }

     else {
         result = 1e18;
        result=min(result, rec(0, start+1, end));
        result=min(result, rec(0, start, end-1));
    }

    dp[turn][start][end]=result;
    return result;
}
int main()
{
cin>>n;
    for(int i=0; i<n; i++){
    cin>>niza[i];
    }
    for(int i = 0; i < 2; i++) {
        for(int j= 0; j <n; j++) {
            for(int k= 0; k < n; k++) {
                dp[i][j][k] = -1;
            }
        }
    }
    memset(dp, -1, sizeof dp);
    cout<<rec(0, 0, n-1);


    return 0;
}