#pragma GCC optimize("Ofast")

#include <bits/stdc++.h>
using namespace std;

#define endl "\n"
//#define int long long

int mod=1e9+7;

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int n,k;
	int ans=0;
	cin>>n>>k;
	priority_queue<int,vector<int>,greater<int>> q;
	for(int i=1;i<=n;i++)
	{
		int a;
		cin>>a;
		ans+=a;
		q.push(a);
	}
	while(k--)
	{
		int num=q.top();
		ans+=num;
		q.pop();
		q.push(num*2);
	}
	cout<<ans<<endl;
}