Roma works in a company that sells TVs. Now he has to prepare a report for the last year.

Roma has got a list of the company's incomes. The list is a sequence that consists of *n* integers. The total income of the company is the sum of all integers in sequence. Roma decided to perform exactly *k* changes of signs of several numbers in the sequence. He can also change the sign of a number one, two or more times.

The operation of changing a number's sign is the operation of multiplying this number by -1.

Help Roma perform the changes so as to make the total income of the company (the sum of numbers in the resulting sequence) maximum. Note that Roma should perform exactly *k* changes.
The first line contains two integers *n* and *k* (1 ≤ *n*, *k* ≤ 10<sup class="upper-index">5</sup>), showing, how many numbers are in the sequence and how many swaps are to be made.

The second line contains a non-decreasing sequence, consisting of *n* integers *a*<sub class="lower-index">*i*</sub> (|*a*<sub class="lower-index">*i*</sub>| ≤ 10<sup class="upper-index">4</sup>).

The numbers in the lines are separated by single spaces. Please note that the given sequence is sorted in non-decreasing order.
import math
from collections import defaultdict  as dt
from sys import stdin
inp    = lambda : stdin.readline().strip()#input()
intinp = lambda : int(inp())#int(input())
mod = int(1e9)+7
inf = float("inf")
listinp= lambda : list(map(int,stdin.readline().split()))#list(input())
mapinp = lambda : map(int,stdin.readline().split())#map(input())
def ce(a,k):
    if(a%k==0):return a//k
    else:return a//k+1

#####  Code Goes hear   #####################
for _ in range(1):
    # n,x=mapinp()
    n,k=mapinp()
    a=listinp()
    a.sort()
    i=0
    while(k>0 and i<n and a[i]<=0 ):
        a[i]*=-1
        k-=1;i+=1
    i-=1   
    # print(a)
    if(k>0 and k%2==1):
        a[i]*=-1
    # print(a)
    print(sum(a))