#define _LIBCPP_DEBUG 0
#include<bits/stdc++.h>
using namespace std;
typedef long long int ll;
ll MOD = 1e9 + 7;
int INF = 1 << 30;

int main(void){
    int N,K; cin>>N>>K;
    vector<int> A(N,0);
    for (int i = 0; i < N; ++i) {
        cin>>A[i];
    }

    sort(A.begin(),A.end());

    int sum=0;
    for (int i = N-K; i < N; ++i) {
        if(A[i]<0) continue;
        sum+=A[i];
    }

    cout<<sum<<endl;

}