def fun(s, n):
    dp = s.copy()
    dp[0] = s[0]
    
    for i in range(1, n):
        for j in range(0, i):
            if s[i] > s[j]:
                dp[i] = max(s[i]+dp[j], dp[i])
    return max(dp)
n = int(input())
a = list(map(int, input().split()))


res = fun(a, n)
print(res)