#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)(n);i++)
using namespace std;
using ll = long long ;
using P = pair<int,int> ;
using pll = pair<long long,long long>;
constexpr int INF = 1e9;
constexpr long long LINF = 1e17;
constexpr int MOD = 1000000007;

int main(){
    int n,k;
    cin >> n >> k;
    vector<int> a(n);
    rep(i,n) cin >> a[i];
    sort(a.begin(),a.end(),greater<int>());
    int ans =0;
    rep(i,min(n,k)){
        if(a[i] > 0) ans += a[i];
        else break;
    }
    cout << ans << endl;
    return 0;
}