/*
ЗАПУСКАЕМ 
░ГУСЯ░▄▀▀▀▄░РАБОТЯГУ░░
▄███▀░◐░░░▌░░░░░░░
░░░░▌░░░░░▐░░░░░░░
░░░░▐░░░░░▐░░░░░░░
░░░░▌░░░░░▐▄▄░░░░░
░░░░▌░░░░▄▀▒▒▀▀▀▀▄
░░░▐░░░░▐▒▒▒▒▒▒▒▒▀▀▄
░░░▐░░░░▐▄▒▒▒▒▒▒▒▒▒▒▀▄
░░░░▀▄░░░░▀▄▒▒▒▒▒▒▒▒▒▒▀▄
░░░░░░▀▄▄▄▄▄█▄▄▄▄▄▄▄▄▄▄▄▀▄
░░░░░░░░░░░▌▌░▌▌░░░░░
░░░░░░░░░░░▌▌░▌▌░░░░░
░░░░░░░░░▄▄▌▌▄▌▌░░░░░ 
 */
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,tune=native")
#pragma GCC optimize("unroll-loops")  
#include <iostream>
#include <complex>
#include <vector>
#include <string>
#include <algorithm>
#include <cstdio>
#include <numeric>
#include <cstring>
#include <ctime>
#include <cstdlib>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <list>
#include <cmath>
#include <bitset>
#include <cassert>
#include <queue>
#include <stack>
#include <deque>
     
      
using namespace std;
template<typename T1, typename T2>inline void chkmin(T1 &x, const T2 &y) { if (x > y) x = y; }
template<typename T1, typename T2>inline void chkmax(T1 &x, const T2 &y) { if (x < y) x = y; } 
template<typename T, typename U> inline ostream &operator<< (ostream &_out, const pair<T, U> &_p) { _out << _p.first << ' ' << _p.second; return _out; }
template<typename T, typename U> inline istream &operator>> (istream &_in, pair<T, U> &_p) { _in >> _p.first >> _p.second; return _in; }
template<typename T> inline ostream &operator<< (ostream &_out, const vector<T> &_v) { if (_v.empty()) { return _out; } _out << _v.front(); for (auto _it = ++_v.begin(); _it != _v.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T> inline istream &operator>> (istream &_in, vector<T> &_v) { for (auto &_i : _v) { _in >> _i; } return _in; }
template<typename T> inline ostream &operator<< (ostream &_out, const set<T> &_s) { if (_s.empty()) { return _out; } _out << *_s.begin(); for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T> inline ostream &operator<< (ostream &_out, const multiset<T> &_s) { if (_s.empty()) { return _out; } _out << *_s.begin(); for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T> inline ostream &operator<< (ostream &_out, const unordered_set<T> &_s) { if (_s.empty()) { return _out; } _out << *_s.begin(); for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T> inline ostream &operator<< (ostream &_out, const unordered_multiset<T> &_s) { if (_s.empty()) { return _out; } _out << *_s.begin(); for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T, typename U> inline ostream &operator<< (ostream &_out, const map<T, U> &_m) { if (_m.empty()) { return _out; } _out << '(' << _m.begin()->first << ": " << _m.begin()->second << ')'; for (auto _it = ++_m.begin(); _it != _m.end(); ++_it) { _out << ", (" << _it->first << ": " << _it->second << ')'; } return _out; }
template<typename T, typename U> inline ostream &operator<< (ostream &_out, const unordered_map<T, U> &_m) { if (_m.empty()) { return _out; } _out << '(' << _m.begin()->first << ": " << _m.begin()->second << ')'; for (auto _it = ++_m.begin(); _it != _m.end(); ++_it) { _out << ", (" << _it->first << ": " << _it->second << ')'; } return _out; }
#define sz(c) (int)(c).size()
#define all(c) (c).begin(), (c).end()
#define rall(c) (c).rbegin(), (c).rend()
#define left left228
#define right right228
#define rank rank228
#define y1 y1228                                                         
#define read(FILENAME) freopen(((string)FILENAME + ".in").c_str(), "r", stdin)
#define write(FILENAME) freopen(((string)FILENAME + ".out").c_str(), "w", stdout)
#define files(FILENAME) read(FILENAME), write(FILENAME)
#define pb push_back
const int MAXN = 100228;


//10:15
//11:55

int n, k;
int x[MAXN];
long long pref[MAXN];

int main() {
    ios_base::sync_with_stdio(false);
    cout.tie(0);
    //read("input");
    cin >> n >> k;
    for (int i = 0; i < n; i++) {
        cin >> x[i];
    }
    vector<int> st, st1;
    for (int i = 0; i < n; i++) {
        if (x[i] >= 0) {
            st.pb(x[i]);
        } else {
            st1.pb(-x[i]);
        }
    }
    sort(all(st));
    sort(all(st1));
    for (int i = 0; i < sz(st); i++) {
        pref[i] = st[i];
    }
    long long ans = 1e18;
    if (sz(st) >= k) {
        chkmin(ans, pref[k - 1]);
    }
    int cur = 0;
    for (int i = 0; i < sz(st1); i++) {
        cur = st1[i];
        if (i + 1 <= k) {
            if (k - i - 1 <= sz(st)) {
                chkmin(ans, (k - i - 1 == 0 ? 0: st[k - i - 1 - 1]) + cur + min(cur, (k - i - 1 == 0 ? 0: st[k - i - 1 - 1])));
            } 
        }
    }
    cout << ans << '\n';
}



Measured memory_bytes: 1912