Sale

Source: Codeforces

Version: Phuoc Hung OJ Extended

Problem Statement

There are $n$ TV sets with prices $a_i$. A negative price means the seller pays you $-a_i$ if you take that TV. You may take at most $m$ sets. Find the maximum amount of money you can earn.

Input

The first line contains $n,m$. The second line contains $n$ integers $a_i$.

Output

Print the maximum amount of money that can be earned.

Subtasks

General constraints:

• $1 \le m \le n \le 100$.

• $-1000 \le a_i \le 1000$.

• Subtask 1 (20 points): $n \le 10$

• Subtask 2 (30 points): $n \le 50$

• Subtask 3 (50 points): No additional constraints.

Examples

Input

5 3
-6 0 35 -2 4

Output

8

Explanation

The TVs priced $-6$ and $-2$ earn $6+2=8$. A third TV is unnecessary because the remaining prices give no additional profit.