#define NOMINMAX
#define TEST_MODE true

#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES

#include "bits/stdc++.h"
#include <regex>

using namespace std;
#define rep(i,n) for(int i=0;i<(int)(n);++i)
#define rep2(i,a,n) for(int i=a;i<(int)(n);++i)
#define rrep(i,n) for(int i=(n)-1;i>=0;--i)
#define reu(i,n) for(int i=1;i<=(int)(n);++i)

#define chmax(a,b) (a=(a)<(b)?(b):(a))
#define chmin(a,b) (a=(a)>(b)?(b):(a))

using ll = long long;
#define all(a) begin(a),end(a)
#define int long long

#ifdef LOCAL_ENV
#define dump(x) cerr<<#x<<" : "<<(x)<< "   \t"
#define dumpl(x) dump(x)<<endl
#define cerr_endl cerr<<endl
ofstream ofstream1("out.txt");
#define cout ofstream1

#else
#define dump(x) 
#define dumpl(x)
#define cerr_endl 
#endif

#define abp(o,a,b) cout<<(((o)?a:b))<<endl
#define YEP(x) abp(x,"YES","NO")
#define Yep(x) abp(x,"Yes","No")

const int inf = (int)1 << 60;
ll mod_n = (int)1e9 + 7;

const int MAX = (int)2e6 + 5;
const int MAX2 = 2005;

template<typename T>void ce_vector(vector<T> a) {
#ifdef LOCAL_ENV
	rep(i, a.size() - 1) cerr << a[i] << " "; cerr << a[a.size() - 1] << endl;
#endif 
}

template<typename T>void ce_vector(vector<pair<T, T>> a) {
#ifdef LOCAL_ENV
	rep(i, a.size()) cerr << a[i].first << "," << a[i].second << " "; cerr << endl;
#endif 
}

template<typename T>void co_vector(vector<T> a) {
	rep(i, a.size() - 1) cout << a[i] << " "; cout << a[a.size() - 1] << endl;
}

template<typename T>void co_vector(vector<pair<T, T>> a) { rep(i, a.size()) cout << a[i].first << "," << a[i].second << " "; cout << endl; }

ll pow_n(ll x, ll n) { ll r = 1; while (n > 0) { if (n & 1)r = (r * x) % mod_n; x = (x * x) % mod_n; n >>= 1; }return r; }


template<typename T>
vector<T> in_vec(int n) {
	vector<T> a(n);
	a.resize(n);
	rep(i, n) cin >> a[i];
	return a;
}

int div_ceil(int a, int b) { int r = a / b; if (a % b != 0)r++; return r; }

ll modular(ll x) {
	return ((x % mod_n + mod_n) % mod_n);
}

// end of templ


void solve() {
	int n, k; cin >> n >> k;
	auto a = in_vec<int>(n);
	sort(all(a));
	reverse(all(a));
	int ans = a[0];
	rep2(i, 1, k) {
		if (a[i] < 0)break;
		ans += a[i];
	}
	cout << ans << endl;
}














signed main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	cout << fixed << setprecision(20);

	solve();

#ifdef LOCAL_ENV
	cout << endl;
	cerr << endl <<"\x1b[7m ↓ \x1b[0m" << endl;
	system("type out.txt");
#endif
	return 0;
}