#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MOD=1000000007;
#define INF 1LL<<30
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define all(x) (x).begin(),(x).end()

int main() {
    int n,k;
    cin>>n>>k;
    vector<int> a(n);
    rep(i,n) cin>>a[i];
    sort(all(a));
    reverse(all(a));
    int ans=0;
    rep(i,k){
        if(a[i]<0) break;
        ans+=a[i];
    }

    cout<<ans<<endl;
}