#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
    int n,k;
    cin >> n >> k;
    vector a(n,0);
    for (int i=0; i<n; i++) cin >> a[i];
    sort(a.rbegin(), a.rend());

    int ans = 0;
    for (int i=0; i<k; i++) ans += max(0, a[i]);
    cout << ans << endl;
}