#include<bits/stdc++.h>
#define rep(i, x) for(ll i = 0; i < x; i++)
#define rep2(i, x) for(ll i = 1; i <= x; i++)
#define all(a) (a).begin(),(a).end()
using ll = long long;
using ld = long double;
using namespace std;
signed main() {
	ll n, m, ans = 0; cin >> n >> m; vector<ll> v(n);
	rep(i, n) { cin >> v[i]; }
	sort(all(v)); reverse(all(v));
	rep2(i, m - 1) { ans += max((ll)0, v[i]); }
	cout << ans + v[0] << endl;
	return 0;
}