#include <cstdio>
#include <cstring>
#include <algorithm>

using namespace std;

int N;
int v[11234];
long long dp[11234][2];

long long solve(int i, int j) {
	if (i > j) {
		return 0;
	}
	if (dp[i][j] != -1) {
		return dp[i][j];
	}
	long long &ret = dp[i][j];
	ret = max(v[i] + min(solve(i + 1, j - 1), solve(i + 2, j)),
			  v[j] + min(solve(i + 1, j - 1), solve(i, j - 2)));
	return ret;
}

bool read() {
	if (scanf("%d", &N) == EOF) {
		return false;
	}
	for (int i = 0; i < N; i++) {
		scanf("%d", &v[i]);
	}
	return true;
}

void process() {
	for (int i = 0; i < N - 1; i++) {
		dp[i][0] = max(v[i], v[i + 1]);
	}
	int turn = 0;
	int pastTurn = 1;
	for (int intervalSize = 4; intervalSize <= N; intervalSize += 2) {
		pastTurn = turn;
		turn = turn ^ 1;
		for (int i = 0, j = intervalSize - 1; j < N; i++, j++) {
			dp[i][turn] = max(v[i] + min(dp[i + 1][pastTurn], dp[i + 2][pastTurn]),
							  v[j] + min(dp[i][pastTurn], dp[i + 1][pastTurn]));
		}
	}
	printf ("%lld\n", dp[0][turn]);
}

int main() {
	while (read()) {
		process();
	}
	return 0;
}