/**
 *    author  : 𝒌𝒚𝒐𝒎𝒖𝒌𝒚𝒐𝒎𝒖𝒑𝒖𝒓𝒊𝒏
 *    created : 2020-03-14 05:18:45
**/

#include <iostream>
#include <deque>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
#include <complex>
#include <numeric>
#include <bitset>
#include <cassert>
#include <cctype>
#include <iomanip>
#include <random>
#include <utility>
#include <chrono>

using namespace std;

using int64 = long long;

template<class T> using binary_heap = std::priority_queue<T, std::vector<T>, std::greater<T>>;
template<class T> std::ostream& operator<<(std::ostream& os, const std::vector<T>& vec) { os << '{'; size_t n = vec.size(); for (size_t i = 0; i < n; ++i) { os << vec[i]; if (i != n - 1) os << ','; } os << '}'; return os; }
template<class T, class U> std::ostream& operator<<(std::ostream& os, const std::pair<T, U>& p) { return os << '{' << p.first << " " << p.second << '}'; }
template<class T, class U> std::ostream& operator<<(std::ostream& os, const std::map<T, U>& mp) { os << '{'; for (auto it = mp.begin(); it != mp.end(); ++it) { os << '{' << it->first << ':' << it->second << '}'; if (it != --mp.end()) os << ','; } os << '}'; return os; }
template<class T> std::ostream& operator<<(std::ostream& os, const std::set<T>& st) { os << '{'; for (auto it = st.begin(); it != st.end(); ++it) { os << *it; if (it != --st.end()) os << ','; } os << '}'; return os; }
template<class T> std::istream& operator>>(std::istream& is, std::vector<T>& vec) { size_t n = vec.size(); for (size_t i = 0; i < n; ++i) is >> vec[i]; return is; }

#define all(_) begin(_), end(_)
#define rall(_) rbegin(_), rend(_)

#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]: ", debug_out(__VA_ARGS__)
#else
#define debug(...) 1728
#endif

void debug_out() { std::cerr << '\n'; }

template <class Head, class... Tail>
void debug_out(Head&& head, Tail&&... tail) {
  std::cerr << head;
  if (sizeof...(Tail) != 0) std::cerr << ", ";
  debug_out(std::forward<Tail>(tail)...);
}

constexpr int64 INF = 1e18;

template <class T>
class CumulativeSum {
 public:
  CumulativeSum(const std::vector<T>& vec) : vec_(vec) { Build(); }

  // return sum of [left, right]
  T Get(int left, int right) {
    return sum_[right + 1] - sum_[left];    
  }

 private:
  std::vector<T> vec_;
  std::vector<T> sum_;

  void Build() {
    sum_.assign(vec_.size() + 1, static_cast<T>(0));
    for (size_t i = 0; i < vec_.size(); ++i) {
      sum_[i + 1] = sum_[i] + vec_[i];
    }
  }
};

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);

  int n, k; cin >> n >> k;
  vector<int64> x(n); cin >> x;

  int64 ans = INF;

  vector<int64> neg, pos;

  for (int i = 0; i < n; ++i) {
    if (x[i] < 0) {
      neg.emplace_back(x[i]);
    } else {
      pos.emplace_back(x[i]);
    }
  }

  for (int i = 0; i < (int) neg.size(); ++i) {
    neg[i] *= -1;
  }

  reverse(all(neg));

  CumulativeSum<int64> cs1(neg);
  CumulativeSum<int64> cs2(pos);

  debug(neg, pos);

  // choose i elements from neg
  for (int i = 0; i <= k; ++i) {
    int64 t = 0;
    int cnt_neg = i, cnt_pos = k - i;
    if (cnt_neg > (int) neg.size() || cnt_pos > (int) pos.size()) continue;
    if (cnt_neg == 0) {
      t += pos[cnt_pos - 1];
    } else if (cnt_pos == 0) {
      t += neg[cnt_neg - 1];
    } else {
      t += neg[cnt_neg - 1] + pos[cnt_pos - 1];
      t += min(neg[cnt_neg - 1], pos[cnt_pos - 1]);
    }
    debug(i, t);
    ans = min(ans, t);
  }

  cout << ans << endl;

  return 0;
}

Measured memory_bytes: 3700