//Normal

#define _GLIBCXX_DEBUG
#define ll long long
#include <bits/stdc++.h>
using namespace std;
using Graph = vector<vector<int>>;

void print(auto a){
  cout << a;
}

void prints(auto a){
  cout << a << " ";
}

void prints(){
  cout << " ";
}

void printl(auto a){
  cout << a << endl;
}

void printl(){
  cout << endl;
}

void fix(int n){
  cout << fixed << setprecision(n);
}

int main(){
  int N, K; cin >> N >> K;
  vector<int> X(N);
  for(int i = 0; i < N; i++) cin >> X[i];
  
  sort(X.rbegin(), X.rend());
  
  int ans = 0;
  int i = 0;
  while(i < K){
    if(X[i] > 0){
      ans += X[i];
    }else{
      if(i == 0) ans += X[i];
      
      break;
    }
    
    i++;
  }
  
  printl(ans);
  
  return 0;
}