Statement

You are given a sequence of positive integers. You may perform any number of moves. In one move, choose one remaining element with value $x$, gain $x$ points, and erase that chosen element together with every element whose value is $x-1$ or $x+1$. Other elements equal to $x$ are not erased, so they may be chosen later.

You may stop at any time. Find the maximum total number of points you can obtain.

Input

The first line contains one integer $n$ ($1 \le n \le 100000$), the length of the sequence.

The second line contains $n$ integers $a_1,a_2,\ldots,a_n$ ($1 \le a_i \le 100000$).

Output

Print one integer: the maximum total number of points obtainable.

Samples

Sample 1

Input:

2
1 2

Output:

2

Sample 2

Input:

3
1 2 3

Output:

4

Sample 3

Input:

9
1 2 3 1 2 2 3 2 2

Output:

10