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.
def produs_cifre(numar):
 
 produs=1
 for i in numar:
  produs=produs*int(i)
 return (produs)
 
def prime_generator(nr_elemente_prime):
 
 vector_prime=[-1]*nr_elemente_prime
 vector_rasp=[0]*nr_elemente_prime
 
 vector_prime[1]=1
 
 vector_rasp[1]=1
#primes sieve 
 contor=2
 
 for i in range(2,nr_elemente_prime):
  if vector_prime[i]==-1:
   vector_prime[i]=1
   vector_rasp[contor]=i
   contor=contor+1
  for j in range(i+i,nr_elemente_prime,i):
    if vector_prime[j]==-1:
     vector_prime[j]=i
   #print(i,j) 
 
 my_set=set(vector_rasp)
 my_set.remove(0)
 my_set.remove(1)
 
 #lista_prime=list(my_set)
 #lista_prime.sort()
 return my_set

#z=int(input())
for contor in range(0,1):
 n,k=list(map(int,input().split()))
 #n=int(input())
 #n,m=list(map(int,input().split()))
 #my_set=set()
 #rasp=''
 lista=list(map(int,input().split()))
# vector=sorted(lista)
 
 cate_zero=0
 minimul=abs(lista[0])
 for i in range(0,n):
  if k>0 and lista[i]<0:
   k-=1
   lista[i]=lista[i]*(-1)
  
  if abs(lista[i])<minimul:
   minimul=abs(lista[i])
   
#print(lista,k,minimul)

if k%2==1:
 print(int(sum(lista)-minimul))
else:
 print(sum(lista))
  