n=int(input())
arr=list(map(int,input().split()))
dp=[0]*(n+1)
dp[1]=arr[0]
for i in range(2,n+1):
    limit=0
    for j in range(1,i):
        tmp=dp[i-j-1]+arr[i-j]
        if limit<tmp:
            limit=tmp
    dp[i]=max(limit,dp[i-1])
print(dp[n])