#include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<map>
#define all(x) x.begin(),x.end()
#define pb push_back
#define ll long long
using namespace std;
int main() {
	int n,k;
	int sum = 0;
	cin >> n>>k;
	vector<int> a(n);
	for (int i = 0; i < n; i++) {
		cin >> a[i];
	}
	sort(all(a), greater<>());
	for (int i = 0; i < k; i++) {
		if (a[i] >= 0) sum += a[i];
		else if (a[0] < 0) {
			sum += a[0];
			break;
		}
	}
	cout << sum << endl;
	return 0;
}