#include<iostream>
#include<algorithm>
#include<queue>
#include<map>
using namespace std;
#define ll long long
const int N = 2010;
void solve() {
	int n,k;
	ll ans = 0;
	cin >> n>>k;
	map<ll, ll>p;
	for (int i = 0; i < n; i++) {
		int a;
		cin >> a;
		ans += a;
		p[a]++;
	}
	while (k--)
	{
		map<ll, ll>::iterator it = p.begin();
		//it--;
		ll t = it->first;
		p[t]--; p[(ll)2 * t]++;
		if (p[t] == 0)p.erase(t);
		ans += t;

	}
	cout << ans << endl;
}
int main() {
	ios::sync_with_stdio(0); cin.tie();
	int T=1;
	//cin >> T;
	while (T--)
	{
		solve();
	}
	return 0;
}