#include<bits/stdc++.h>
#include<unordered_set>
#include<unordered_map>
using namespace std;
#define int long long
#define REP(i,m,n) for(int i=(m);i<(n);i++)
#define rep(i,n) REP(i,0,n)
#define pb push_back
#define all(a) a.begin(),a.end()
#define rall(c) (c).rbegin(),(c).rend()
#define mp make_pair
#define endl '\n'
typedef long long ll;
typedef pair<ll,ll> pll;
typedef long double ld;
const ll inf=1e9+7;
const ll mod=1e9+7;
signed main(){
    ll n,k;cin>>n>>k;
    vector<ll>a(n);
    rep(i,n)cin>>a[i];
    sort(rall(a));
    ll ans=0;
    ll i=0;
    ll cnt=0;
    while(a[i]>0&&i<n&&cnt<k){
        if(a[i]>=0){
            ans+=a[i];
            cnt++;
        }
        i++;
    }
    cout<<ans<<endl;
}