#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for(int i = 0; i < n; i++)
#define rep2(i, x, n) for(int i = x; i <= n; i++)
#define rep3(i, x, n) for(int i = x; i >= n; i--)
#define each(e, v) for(auto &e: v)
#define pb push_back
#define eb emplace_back
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sz(x) (int)x.size()
using ll = long long;
using pii = pair<int, int>;
using pil = pair<int, ll>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
const int MOD = 1000000007;
//const int MOD = 998244353;
const int inf = (1<<30)-1;
const ll INF = (1LL<<60)-1;
template<typename T> bool chmax(T &x, const T &y) {return (x < y)? (x = y, true) : false;};
template<typename T> bool chmin(T &x, const T &y) {return (x > y)? (x = y, true) : false;};

struct io_setup{
    io_setup(){
        ios_base::sync_with_stdio(false);
        cin.tie(NULL);
        cout << fixed << setprecision(15);
    }
} io_setup;

int main(){
    int N, K; cin >> N >> K; K = N-K;

    vector<ll> A(N);
    rep(i, N) {cin >> A[i]; A[i] *= 2;}

    ll ans = INF;
    vector<ll> L(N+1, 0), R(N+1, 0);
    rep(i, N) L[i+1] = L[i]+A[i];
    rep3(i, N-1, 0) R[i] = R[i+1]+A[i];

    vector<ll> P;
    P.eb(A[0]);
    rep(i, K) P.eb((A[i]+A[i+N-K])/2);

    rep(i, N){
        int l = upper_bound(all(P), A[i])-begin(P)-1, r = K-l;
        ll tmp = 0;
        tmp += L[l], tmp -= A[i]*l;
        tmp -= R[N-r], tmp += A[i]*r;
        tmp += R[i]-R[N-r], tmp -= A[i]*(N-i-r);
        tmp -= L[i]-L[l], tmp += A[i]*(i-l);
        chmin(ans, tmp);
    }

    cout << ans/2 << '\n';
}