#include 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; using pil = pair; using pli = pair; using pll = pair; const int MOD = 1000000007; //const int MOD = 998244353; const int inf = (1<<30)-1; const ll INF = (1LL<<60)-1; template bool chmax(T &x, const T &y) {return (x < y)? (x = y, true) : false;}; template 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 A(N); rep(i, N) {cin >> A[i]; A[i] *= 2;} ll ans = INF; vector 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 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'; }