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.

Input

The first line contains two integers $*n*$ and $*k*$ $(1 ≤ *n*, *k* ≤ 10^{5})$, 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 $*a*_{*i*}$ $(|*a*_{*i*}| ≤ 10^{4})$.

The numbers in the lines are separated by single spaces. Please note that the given sequence is sorted in non-decreasing order.

Output

In the single line print the answer to the problem — the maximum total income that we can obtain after exactly $*k*$ changes.

Note

In the first sample we can get sequence [1, 1, 1], thus the total income equals $3$.

In the second test, the optimal strategy is to get sequence [-1, 1, 1], thus the total income equals $1$.