// распродажа
#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
using namespace std;
int main()
{
    vector <int> mv;
    int n, m, sum = 0;
    cin >> n;
    cin >> m;
    int a;
    for (int i = 0; i < n; i++) {
        cin >> a;
        mv.push_back(a);
    }
    sort (mv.begin(), mv.end());
    for (int i = 0; i < m; i++) {
        sum = sum + mv[i];
    }
    cout << sum * -1;
    return 0;
}