#include<bits/stdc++.h>
#define rep(i,N) for(int i=0;i<(N);i++)
#define rrep(i, n) for (int i = (int)n-1; i >= 0; --i)
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
using namespace std;
const long long MOD = 1e9 + 7;
const long long INF = 1e12;
const int inf = 1e9;
const int mod = 1e9+7;
typedef long long ll;
typedef pair<ll,int> P;
typedef set<int> S;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

__attribute__ ((constructor))
void fastio() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(10);
}

int main(){
    int n;
    ll k;
    cin >> n >> k;
    vector<ll> a(n);
    rep(i, n) cin >> a[i];

    vector<ll> ab;
    rep(i, n) ab.push_back(abs(a[0] - a[i]));

    sort(ab.begin(), ab.end());

    ll ans = 0;

    rep(i, k) { 
        ans += ab[i]; 
    }

    FOR(i, k, n) {
        ans -= ab[i]; 
    }

    cout << ans << endl;
    return 0;
}