// #define DEBUG_ON

#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
#define timer_start()                          \
  chrono::system_clock::time_point start, end; \
  start = chrono::system_clock::now();
#define timer_wrap()                                                     \
  end = chrono::system_clock::now();                                     \
  double time = static_cast<double>(                                     \
      chrono::duration_cast<chrono::microseconds>(end - start).count() / \
      1000.0);                                                           \
  printf("time %lf[ms]\n", time);                                        \
  start = end;
#define optimize_cin() \
  cin.tie(0);          \
  ios::sync_with_stdio(false)
using namespace std;
using ll = long long;
#define INF 1000000000  // 10^9
template <class T>
bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}
int main() {
  // input
  int n, k;
  cin >> n >> k;
#ifdef DEBUG_ON
  timer_start();
#endif

  vector<int> a(n);
  for (int i = 0; i < n; i++) {
    cin >> a.at(i);
  }

  int sum = 0;
  sort(a.begin(), a.end());
  for (int i = a.size() - 1; i >= (n - k); i--) {
    if (a.at(i) < 0) {
      break;
    }
    sum += a.at(i);
  }

  cout << sum << endl;

#ifdef DEBUG_ON
  timer_wrap();
#endif
  return 0;
}