#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int pizzaAmount;
vector<int> pizzaPieces;
//三维数组，result[left][right][0]表示吃货能吃到的最大数，result[left][right][1]表示馋嘴能吃到的最大数
vector<vector<vector<unsigned long>>> result;

//披萨是一个圆，通过这个函数让数组首尾相接
int legalIndex(int input) {
	if (input < 0)
		return pizzaAmount - 1;
	else if (input >= pizzaAmount)
		return 0;
	return input;
}

//返回从left到right，某人能吃到的最大的披萨，turn=0表示吃货，turn=1表示馋嘴
unsigned long getMax(int left, int right, int turn)
{
	if (left == right)
	{
		//最后一块饼，因为pizza数为奇数，吃货先吃，所以他必定比馋嘴多吃一个也就是最后这一个
		if (turn == 0)
			return pizzaPieces[left];
		else
			return 0;
	}
	//如果已有结果则直接返回
	if (result[left][right][turn] > 0)
		return result[left][right][turn];
	//吃货的回合，选择两种情况下（吃左边/吃右边）最大的
	if (turn == 0)
	{
		unsigned long eatLeft = getMax(legalIndex(left - 1), legalIndex(right), 1) + pizzaPieces[left];
		unsigned long eatRight = getMax(legalIndex(left), legalIndex(right + 1), 1) + pizzaPieces[right];
		result[left][right][0] = max(eatLeft, eatRight);

	}
	//馋嘴的回合，在左和右两个选择中固定选最大的
	else
	{
		if (pizzaPieces[left] > pizzaPieces[right])
			result[left][right][1] = getMax(legalIndex(left - 1), right, 0);
		else
			result[left][right][1] = getMax(left, legalIndex(right + 1), 0);

	}
	return result[left][right][turn];
}

int main(int argc, char *argv[])
{
	cin >> pizzaAmount;
	for (int i = 0; i < pizzaAmount; i++)
	{
		int temp;
		cin >> temp;
		pizzaPieces.push_back(temp);
	}
	//初始化三维数组
	result = vector<vector<vector<unsigned long>>>(pizzaAmount, vector<vector<unsigned long>>(pizzaAmount, vector<unsigned long>(2, 0)));

	unsigned long max = 0;
	for (int i = 0; i < pizzaAmount; i++)
	{
		//一开始从吃货开始吃
		unsigned long get = getMax(legalIndex(i - 1), legalIndex(i + 1),1)+pizzaPieces[i];
		if (get > max)
			max = get;
	}
	cout << max << endl;
	
	return 0;
}