#include <algorithm>
#include <cstring>
#include <deque>
#include <iostream>
#include <limits>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>
#define rep(i, a, n) for(int i = a; i < n; i++)
using namespace std;
using ll = long long;
using P = pair<int, int>;

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