import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;

public class Main{
	public static int max(int a, int b) {
		if(a>=b) return a;
		else return b;
	}
    public static void main(String args[]) throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));

        int cass = Integer.parseInt(br.readLine());

        String pp[] = br.readLine().split(" ");
        int[] ppp = new int[cass+1];
        for(int i=0;i<cass;i++) {
        	ppp[i+1] = Integer.parseInt(pp[i]);
        }

        int[] arr = new int[cass+1];
        arr[0] = 0;
        arr[1] = ppp[1];

        for(int i=2;i<cass+1;i++){
        	int maax = ppp[i];
            for(int j=1;j<(i/2)+1;j++) {
            	maax = max(arr[j]+arr[i-j],maax);
            	arr[i] = maax;
            }
        }

        bw.write(arr[cass]+"");
        bw.flush();
        bw.close();
    }
}