#include <iostream>
#include <algorithm>
#include <numeric>
#include <vector>

void solve() {
    int n, k;
    std::cin >> n >> k;

    std::vector<int> xs(n);
    for (auto& x : xs) std::cin >> x;
    std::sort(xs.rbegin(), xs.rend());

    int sum = 0;
    for (int i = 0; i < k; ++i) {
        if (i > 0 && xs[i] < 0) break;
        sum += xs[i];
    }

    std::cout << sum << std::endl;
}

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    solve();

    return 0;
}