#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <queue>
#include <cmath>
#include <climits>
#include <iomanip>
#include <set>
#include <map>
using namespace std;
typedef long long ll;
int main(){
    ll n,k;
    cin >> n >> k;
    vector<ll> a(n);
    for(int i = 0;i < n;i++)cin >> a[i];
    sort(a.rbegin(),a.rend());
    ll res = 0;
    for(int i = 0;i < k;i++){
        if(a[i] <= 0 && i != 0)break;
        res += a[i];
    }
    cout << res << endl;
}