#include<bits/stdc++.h> using namespace std; int n,k,a[1001],b[1001],len,s; int main() { cin>>n>>k; for(int i=1;i<=n;i++) { cin>>a[i]; if(a[i]<0) { b[++len]=abs(a[i]); a[i]=0; } } sort(a+1,a+1+n); sort(b+1,b+1+len); for(int i=1;i<=n;i++) { if(a[i]<len+1) { a[i]=abs(b[len-i+1]); } if(a[i]<0&&k>0) { a[i]=abs(a[i]); } if(a[i]>=0&&k%2==1) { a[i]=abs(a[i]); } s+=a[i]; } cout<<s; return 0; }