#include <bits/stdc++.h>
using namespace std;

#define ll long long int
#define pb push_back
#define mp make_pair
#define mod 1000000007

ll power(ll a,ll b){ll ans=1;while(b>0){if(b&1){ans = (ans*a);}b>>=1;a=a*a;}return ans;}
ll gcd(ll a,ll b){if(b==0){return a;}return gcd(b,a%b);}
bool comp(ll a,ll b){
   return a>b;
}
int main() {
   ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0);
   // cout << fixed << setprecision(10);
   ll n,k;
   cin>>n>>k;
   ll arr[n];
   for(ll i=0;i<n;i++){
      cin>>arr[i];
   }
   sort(arr,arr+n,comp);
   ll sum=0;
   for(ll i=0;i<k;i++){
      if(arr[i]<=0 && i==0){
         sum =arr[i];
         break;
      }
      if(arr[i]<0){
         break;
      }else{
         sum += arr[i];
      }
   }
   cout<<sum<<endl;
	return 0;
}