#include<algorithm>
#include<cstring>
#include<string>
#include<cassert>
#include<cmath>
#include<climits>
#include<iomanip>
#include<stack>
#include<unordered_map>
#include<bitset>
#include<limits>
#include<complex>
#include<array>
#include <iostream>

using namespace std;
#define rep(i,m,n) for(int (i)=(int)(m);i<(int)(n);i++)
#define REP(i,n) rep(i,0,n)
#define ll long long
#define ull unsigned long 

#define ull unsigned long long
int main()
{
  ll N,K,sum;
  cin >> N >> K;
  sum = 0;
  ll A[105];
  for(ll i=0;i < N;i++)
    cin >> A[i];
  sort(A,A+N);
  for(ll i=0;i < K;i++)
    if(A[N-i-1] >= 0)
    sum=  sum + A[N-i-1];
  if(A[N-1]<0) sum=A[N-1];
  cout << sum  << endl;
  
}