#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main()
{
  int n, k;
  cin >> n >> k;
  vector<int> a(n);
  for (int i = 0; i < n; i++)
    cin >> a[i];
  sort(begin(a), end(a), greater<int>());
  int sum = 0;
  for (int i = 0; i < k; i++)
  {
    if (a[i] <= 0)
    {
      if (i == 0)
        sum += a[i];
      break;
    }
    sum += a[i];
  }
  cout << sum << endl;
  return 0;
}