Freakin' news has recently claimed that they have discovered a civilization on mars and that they have established contact with the martians. Following is a summary of the dawn hour breakin' news on freakin' news : 
 Occassionally, the martian ministers feel the need to please their king. For this purpose, they give the king a trivial problem to solve and heap excessive praise upon him when he presents the correct solution. 
 This time they have given the king the following problem : 
Given two positive integers n,k and n numbers a[1],a[2],...a[n] find the maximum of (b[1]a[1]+b[2]a[2]+.....b[n]a[n]) subject to the restrictions : 
1) b[i] is either 1 or (-1), for all i, 1 ≤ i ≤ n. 
2) Exactly k b[i]'s are 1. The remaining (n-k) b[i]'s are (-1). 
 To make the task even easier for the king, the ministers have given the king the sequence a[1],a[2],...a[n] sorted in non-decreasing order. 

 The king, being lazy, has outsourced the task to freakin' news. Your job is to do this task for freakin' news. 

 Input Format : 

The first line of input contains a single integer n. The next line consists of n space seperated integers a[1], a[2], ... a[n]. The sequence a is guaranteed to be sorted in non-decreasing order. 

 Output Format : 

On the only line of output, output a single integer : the maximum of (b[1]a[1]+b[2]a[2]+.....b[n]a[n]) subject to restrictions 1 and 2. 

 Constraints : 

2 ≤ n ≤ 100 
0 ≤ k ≤ n 
|a[i]| ≤ 1000 
The sequence a is sorted in non-decreasing order i.e. a[1] ≤ a[2] ≤ .... ≤ a[n] 

 Sample Input : 
2 1 
-4 -4 

 Sample Output : 
0 

 Sample Input : 
2 0 
-2 5 

 Sample Output : 
-3 

 Explanation : 
1 : There are two possibilities for the sequence b : (+1,-1) and (-1,+1). Both lead to sum 0. 
2 : There is only one possibility for the sequence b : (-1,-1). This leads to the sum -3.
l = raw_input().split()
n, k = int(l[0]), int(l[1])
l = raw_input().split()
l = [int(i) for i in l]
a, b = 1, -1
ans = -1*sum(l[:n-k])+sum(l[n-k:])
print ans