#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("YES");}else{puts("NO");}
#define MAX_N 200005

int main() {
    int n, k;
    cin >> n >> k;
    int a[n];
    rep(i,n)cin >> a[i];
    sort(a,a+n,greater<int>());
    int ans = 0;
    rep(i,k){
        if(a[i] < 0)break;
        ans += a[i];
    }
    cout << ans << endl;
    return 0;
}