#include <bits/stdc++.h>
using namespace std;
#define REP(i,a,n) for(int i=(a); i<(int)(n); i++)
#define rep(i,n) REP(i,0,n)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it)
#define ALLOF(c) (c).begin(), (c).end()
typedef long long ll;
typedef unsigned long long ull;

ll f(ll x, vector<int>& v, int K){
  vector<ll> ret;
  rep(i,v.size()){
    ret.push_back(abs(v[i]-x));
  }
  sort(ALLOF(ret));
  ll sum = 0;
  rep(i,v.size()){
    if(i<K) sum += ret[i];
    else sum += -ret[i];
  }
  return sum;
}

int main(){
  int N, K;
  cin >> N >> K;
  vector<int> v(N);
  rep(i,N) cin >> v[i];

  ll ret = f(v[N/2],v,K);
  ret = min(ret, f(v[0],v,K));
  ret = min(ret, f(v[N-1],v,K));

  cout << ret << endl;
  
  return 0;
}