// No.1046 Fruits Rush
#include <bits/stdc++.h>
#define rep(i, n) for(int i=0; i<(int)(n); i++)
using namespace std;
using ll = long long;
using ull = unsigned long long;

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