#include <bits/stdc++.h>
using namespace std;

int main() {
	int n, k;
	cin >> n >> k;
	vector<int> a(n);
	for (int &e : a) cin >> e;
	sort(a.begin(), a.end(), greater<int>());
	
	int ans = a[0];
	for (int i = 1; i < k; i++) {
		if (a[i] < 0) break;
		ans += a[i];
	}
	
	cout << ans << '\n';
	
	return 0;
}