#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0; i<(n); ++i)
using ll = long long;

int main(){
    int n,k; cin >> n >> k;
    vector<int> a(n);
    rep(i,n) cin >> a[i];
    sort(a.rbegin(), a.rend());

    int ans = 0;
    rep(i,k){
        if(i==0){
            ans += a[i];
            continue;
        }
        if(a[i]>0) ans += a[i];
    }

    cout << ans << endl;
}