#include<stdio.h>


int value[1001];
int DP[1001];

int main()
{
	int max = 0, N;

	scanf("%d", &N);

	for (int a = 1; a <= N; a++) {
		scanf("%d", &value[a]);
		DP[a] = value[a];
	}

	for (int a = 2; a <= N; a++) {
		for (int b = 1; b <= a; b++) {
			max = DP[b] + value[a - b];
			if (max > DP[a])
				DP[a] = max;
		}
	}

	printf("%d\n", DP[N]);
	return 0;
}