#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main()
{
	int n,k;
	cin>>n>>k;
	int cn = 0;
	int money = 0;
	vector<int>P;
	for(int i = 0;i<n;i++){
		int p;
		cin>>p;
		P.push_back(p);
	}
	sort(P.begin(),P.end());
	while(cn<n){
		money += P[cn];
		int inflation = P[cn];
		for(int i = n-1; i>max(n-1-k,cn);i--){
			P[i] += inflation;
		}
		cn++;
	}
	cout<<money<<endl;
	return 0;
}