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.
giris =input()
giris = giris.split(" ")
giris = list(map(int, giris))
sayilar =input()
sayilar = sayilar.split(" ")
sayilar = list(map(int, sayilar))
sayilar.sort()
if giris[0] > giris[1]:
    for i in range(int(giris[1])):
        sayilar[i] *= -1
    total = sum(sayilar)
    print(total)
else:
    giris[0] < giris[1]
    a =giris[1] // giris[0]
    if a >2 and a //2 == 0:
        k =giris[1] - giris[0]
        for i in range(int(k)):
            sayilar[i] *= -1
        total = sum(sayilar)
        print(total)
    else:
        j =giris[1] - giris[0]
        for i in range(int(j)):
            sayilar[i] *= -1
        total = sum(sayilar)
        print(total)

#değiştirilmesini istediği eleman sayısı listenin uzunluğpundna fazla olursa değişim sayısı/list len . 
#eğer sonuç tam sayı olarak çift ise değişmez tek ise bütün lsite negatif olur ve değişim - list len = kadar sıfırdan başlar