#include <bits/stdc++.h>
#define rep(i,a,b) for(int i=int(a);i<=int(b);++i)
using namespace std;
template<class A>void pr(A a){cout << (a) << endl;}
template<class A,class B>void pr(A a,B b){cout << a << " "  ;pr(b);}
template<class A,class B,class C>void pr(A a,B b,C c){cout << a << " " ;pr(b,c);}
template<class A,class B,class C,class D>void pr(A a,B b,C c,D d){cout << a << " " ;pr(b,c,d);}
typedef long long ll;
typedef pair<ll, ll> l_l;
typedef pair<int, int> i_i;
int INF=numeric_limits<int>::max();
// for(int j=0;j<N;++j) {

int main(void) {
int n,k;cin>>n>>k;
ll ans=0;
int a[n+10];
int A;
rep(i,0,n-1) {
  cin>>A;
  a[i]=A;
}
sort(a,a+n,greater<int>());
rep(i,0,k-1) {
  if(a[i]>0) ans+=a[i];
  else break;
}
pr(ans);
  return 0;
}