#include <bits/stdc++.h>
#define rep(i, ss, ee) for (int i = ss; i < ee; ++i)
using namespace std;

void solve() {
  int N, K, sum = 0;
  cin >> N >> K;
  vector<int> v(N);
  rep(i, 0, N) { cin >> v[i]; }
  sort(v.begin(), v.end(), greater{});
  rep(i, 0, K) if (v[i] > 0) sum += v[i];
  cout << sum << endl;
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  solve();
  getchar();
}