#include <bits/stdc++.h>
#define ll long long
using namespace std;
#define rep(i, n) for (int i = 0; i < n; i++)
#define rrep(i, n) for (int i = 1; i <= n; i++)
ll gcd(ll a, ll b) { return b ? gcd(b, a%b) : a; }
ll lcm(ll a, ll b) { return (a * b) / gcd(a,b); }
using P = pair <int, int>;
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; }
 
ll MOD = 1000000007;
ll INF =1<<30;
ll dp[110][100100];
 

int main(){
   int n , k ;
   cin >>  n >>k;
   vector<int>a;
   int x=-101;
   rep(i,n){
       int b;
       cin >> b;
       if(b>=0) a.push_back(b);
       if(b>x&&b<0) x = b;
   }
   sort(a.begin(),a.end(),greater<int>());
   if(a.size()==0){ cout << x <<endl; return 0;}
   int ans = 0;
   if(k>=a.size()){
       rep(i,a.size()) ans+=a[i];
       cout << ans <<endl;
   }
   else{
       rep(i,k) ans+=a[i];
       cout <<ans <<endl;
   }
   
}