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Time Limit: 2 s Memory Limit: 256 MB Total points: 100

#22579. Treats for the Cows

Statistics

FJ has purchased $N$ $(1 \le N \le 2000)$ yummy treats for the cows who get money for giving vast amounts of milk. FJ sells one treat per day and wants to maximize the money he receives over a given period of time.

The treats are interesting for many reasons:

  • The treats are numbered $1..N$ and stored sequentially in a single file in a long box that is open at both ends. On any day, FJ can retrieve one treat from either end of his stash of treats.
  • Like fine wines and delicious cheeses, the treats improve with age and command greater prices.
  • The treats are not uniform: some are better and have higher intrinsic value. Treat $i$ has value $v(i)$ ($1 \le v(i) \le 1000$).
  • Cows pay more for treats that have aged longer: a cow will pay $v(i)*a$ for a treat of age $a$.

Given the values $v(i)$ of each of the treats lined up in order of the index $i$ in their box, what is the greatest value FJ can receive for them if he orders their sale optimally?

The first treat is sold on day 1 and has age $a=1$. Each subsequent day increases the age by 1.

Input

  • Line 1: A single integer, $N$.
  • Lines $2..N+1$: Line $i+1$ contains the value of treat $v(i)$.

Output

  • Line 1: The maximum revenue FJ can achieve by selling the treats.

Examples

Input 1

5
1
3
1
5
2

Output 1

43

FJ sells the treats (values 1, 3, 1, 5, 2) in the order of indices 1, 5, 2, 3, 4, making $1*1 + 2*2 + 3*3 + 4*1 + 5*5 = 43$.

Problem by Marco Gallotta (2005).

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