import java.util.*;
import java.lang.*;
import java.io.*;

class sushi {
	
	private static final int MAX_N = 1000;
	static int n; // sushiの数
	static int v[] = new int[MAX_N]; //sushiの価値
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		n = sc.nextInt();
		for (int i = 0; i < n; i++) {
			v[i] = sc.nextInt();
		}
		sc.close();
		System.out.println(eat(0, -2));
		
	}
	static int eat(int i,int j) {
		int ret;
		// 皿がない場合
		if (i == n) {
			ret = 0;
		// 食べたらダメな皿の場合
		} else if (i == j + 1) {
			ret = eat(i+1, j);
		} else {
			// 食べた場合と食べなかった場合を比べる
			if (i == n -1) {
				ret = eat(i+1, i) + v[i];
			} else {
				int tmp1 = eat(i+1, i) + v[i];
				int tmp2 = eat(i+1, j);
				ret = (tmp1 < tmp2) ? tmp2:tmp1;
				//ret = Math.max(eat(i+1, i) + v[i], eat(i+1, j));
				
			}
			
		}
		return ret;
	}
}