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 sys,os,io
import math 
from bisect import bisect_left as bl
from collections import defaultdict
def ii():
    return int(input())
def li():
    return list(map(int,input().split()))
if(os.path.exists('input.txt')):
    sys.stdin = open("input.txt","r") ; sys.stdout = open("output.txt","w") 
else:
    input = io.BytesIO(os.read(0, os.fstat(0).st_size)).readline
n,k = li()
a = li()
k1 = k 
# print(a)
for i in range(min(n,k1)):
    if a[i]<0:
        a[i]=-a[i] 
        # print(i,"f",a[i])
        k-=1 

if k>0:
    if 0 in a:
        k = 0
    if k%2==0:
        k = 0 
    else:
        a.sort()
        a[0] = -a[0]
print(sum(a))

