#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main(){
    int n,m;cin>>n>>m;
    vector<int> A(n);
    for(int i = 0; n > i; i++){
        cin>>A[i];
    }
    sort(A.begin(),A.end(),greater<int>());
    int i = 0;
    int a = 0;
    while(m--&&A[i]>0){
        a+=A[i];
        i++;
    }
    cout << a << endl;
}