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.
# from collections import defaultdict
n, k = map(int, input().split())
arr = list(map(int, input().split()))
ans = 0
# map1 = defaultdict(int)
if n == 1:
    if arr[0] >= 0:
        if k % 2 != 0:
            ans -= arr[0]
        else:
            ans = arr[0]
    if arr[0] < 0:
        if k % 2 != 0:
            ans -= arr[0]
        else:
            ans = arr[0]
else:
    i = 0
    while i < len(arr):
        if k != 0:
            if arr[i] >= 0:
                if i > 1:
                    if abs(arr[i-1]) >= arr[i]:
                        temp = arr[i]
                    else:
                        arr[i-1] = abs(arr[i-1])
                        ans -= arr[i-1]
                        temp = arr[i-1]
                        i = i-1
                else:
                    temp = arr[i]
                if k % 2 != 0:
                    ans -= temp
                else:
                    ans += temp
                k = 0
            if arr[i] < 0:
                ans += abs(arr[i])
                k -= 1
        else:
            ans += arr[i]
        i += 1
print(ans)


#     map1[arr[i]] += 1
# if k >= map1[-1]:
#     k = k-map1[-1]
#     if k % 2 != 0:
#         print(n-2)
#     else:
#         print(n)
# else:
#     print(map1[1]+k-map1[-1]+k)
