#include <iostream>
#include <vector>
#include <climits>
#include <algorithm>
#include <cmath>
#include <map>
#include <set>
#include <string>
#include <bitset>
#include <utility>
#include <numeric>
#include <queue>
#include <stack>

using ll = long long;
using namespace std;

constexpr int MOD = 1e9 + 7;
constexpr ll MOD_LL = ll(1e9) + 7;

int main(void) {
	int n, k;
	cin >> n >> k;
	
	vector<int> a(n);
	for(int i = 0; i < n; ++i) {
		cin >> a[i];
	}
	
	sort(a.begin(), a.end(), greater<int>());
	
	int ans = 0;
	
	if( a[0] <= 0 ) {
		cout << a[0] << endl;
	} else {
		for(int i = 0; i < k; ++i) {
			if( a[i] > 0 ) {
				ans += a[i];
			} else {
				break;
			}
		}
		
		cout << ans << endl;
	}
	
	return 0;
}