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
input = sys.stdin.readline

############ ---- Input Functions ---- ############
def inp(): # int
    return(int(input()))
def inlt(): # list
    return(list(map(int,input().split())))
def insr(): # string as char list
    s = input()
    return(list(s[:len(s) - 1]))
def instr(): # string
    return input()
def invr(): # spaced ints
    return(map(int,input().split()))

n, k = list(invr())
vals = list(invr())
i = 0
while i < k and i < n and vals[i] < 0:
    vals[i] *= -1
    i += 1


if (k - i) % 2 == 0:
    print(sum(vals))
else:
    print(sum(vals) - 2 * min(vals))
# # case 1: i == k (used all swaps)
# # return sum
#
#
# if i == k:
#     print(sum(vals))
#
#
# # case 2: i == n: swapped everything, everything now positive
# # use up rest of swaps in pairs, then reswap the smallest element
# elif i == n:
#
# # case 3: i < k, i < n, vals[i] >= 0: pair and reswap smallest element
#
# # ops_remaining = k - i
# if (k - i) % 2 == 0:
#     print(sum(vals))
# else:
#
