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 $*a*_{*k*}$) and delete it, at that all elements equal to $*a*_{*k*} + 1$ and $*a*_{*k*} - 1$ also must be deleted from the sequence. That step brings $*a*_{*k*}$ 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 $*n*$ ($1 ≤ *n* ≤ 10^{5}$) that shows how many numbers are in Alex's sequence.

The second line contains $*n*$ integers $*a*_{1}$, $*a*_{2}$, ..., $*a*_{*n*}$ ($1 ≤ *a*_{*i*} ≤ 10^{5}$).

Output

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

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.