#include <algorithm>
#include <cmath>
#include <cstdio>
#include <deque>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>

using namespace std;

typedef long long ll;

#define MOD 1000000007

int main() {
  int n, k;
  cin >> n >> k;
  vector<int> a(n);
  for (int i = 0; i < n; ++i) {
    cin >> a[i];
  }
  sort(a.rbegin(), a.rend());
  int ans = 0;
  for (int i = 0; i < k; ++i) {
    if (i == 0) {
      ans += a[i];
    } else {
      if (0 <= a[i]) {
        ans += a[i];
      }
    }
  }
  cout << ans << endl;
  return 0;
}