#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(LL i = a;i<b; i++)
#define rrep(i,a,b) for(LL i = a;i>=b; i--)
#define INF ((1LL<<62)-(1LL<<31))
#define ooki 9,223,372,036,854,775,807
#define tii -9,223,372,036,854,775,808
typedef long long LL;
int main(){
 int n,k,sum=0;
  cin>>n>>k;
  vector<int> a(n);
  rep(i,0,n){cin>>a[i];}
  sort(a.begin(),a.end());
  reverse(begin(a),end(a));
  if(a[0]<0){cout<<a[0]<<endl;return 0;}
  rep(i,0,k){if(a[i]>0&&a[i]){sum+=a[i];}}
     cout<<sum<<endl;
  
  
}