A movie rating website is hacked to $maximize$ the total rating of a particular show. The hacker decides to flip (negative becomes positive and vice versa) the sign of K ratings. He has to perform exactly K flips on N ratings stored in the database. The flips may or may not be optimal. He can also flip the sign of the same rating more than once.

Write a program to calculate the highest possible total rating of the show.

Input format
First line : Two space-separated integers, N and K
second line : N space-separated integers denoting the ratings

Output format
Print the highest possible rating.

Constraints
$1\le N\le 10^7$
$1\le K\le 10^7$
$-10\le Rating \le 10$