#include <cstdio>
#include <iostream>
#include <string>
#include <sstream>
#include <stack>
#include <algorithm>
#include <cmath>
#include <queue>
#include <map>
#include <set>
#include <cstdlib>
#include <bitset>
#include <tuple>
#include <assert.h>
#include <deque>
#include <bitset>
#include <iomanip>
#include <limits>
#include <chrono>
#include <random>
#include <array>
#include <unordered_map>
#include <functional>
#include <complex>
#include <numeric>

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

constexpr long long MAX = 5100000;
constexpr long long INF = 1LL << 60;
constexpr int inf = 1000000007;
//constexpr long long mod = 1000000007LL;
constexpr long long mod = 998244353LL;

using namespace std;
typedef unsigned long long ull;
typedef long long ll;

int main()
{
	/*
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
    */

	int n, k; scanf("%d %d", &n, &k);
	priority_queue<ll> pq;
	for (int i = 0; i < n; i++) {
		ll x; scanf("%lld", &x);
		pq.emplace(x);
	}
	ll res = pq.top();
	pq.pop();
	k--;
	while (k--) {
		if (pq.top() > 0) {
			res += pq.top();
			pq.pop();
		}
		else {
			break;
		}
	}
	cout << res << endl;
	return 0;
}