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

int main() {
	int N, K; cin >> N >> K;
	int A[100]; rep(i, N) cin >> A[i];
	sort(A, A + N, greater<int>());
	int ans = 0;
	rep(i, K) {
		if (i != 0) if (A[i] < 0) break;
		ans += A[i];
	}
	cout << ans << endl;

	return 0;
}