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# Boredom

1000ms 262144K

## Description:

Alex doesn't like boredom. That's why whenever he gets bored, he comes up with games. One long winter evening he came up with a game and decided to play it.

Given a sequence a consisting of n integers. The player can make several steps. In a single step he can choose an element of the sequence (let's denote it ak) and delete it, at that all elements equal to ak + 1 and ak - 1 also must be deleted from the sequence. That step brings ak points to the player.

Alex is a perfectionist, so he decided to get as many points as possible. Help him.

## Input:

The first line contains integer n (1 ≤ n ≤ 105) that shows how many numbers are in Alex's sequence.

The second line contains n integers a1, a2, ..., an (1 ≤ ai ≤ 105).

## Output:

Print a single integer — the maximum number of points that Alex can earn.

## Sample Input:

21 2

## Sample Output:

2

## Sample Input:

31 2 3

## Sample Output:

4

## Sample Input:

91 2 1 3 2 2 2 2 3

## Sample Output:

10

## Note:

Consider the third test example. At first step we need to choose any element equal to 2. After that step our sequence looks like this [2, 2, 2, 2]. Then we do 4 steps, on each step we choose any element equals to 2. In total we earn 10 points.

Info

Provider CodeForces

Code CF455A

Tags

dp

Submitted 156

Passed 64

AC Rate 41.03%

Date 03/03/2019 22:39:44

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