#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>

#include <algorithm>
#include <bitset>
#include <complex>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>

#include <cassert>
#include <functional>

using ll = long long;
using namespace std;

template<typename A, typename B>
bool chmin(A &a, const B b) {
  if (a <= b) return false;
  a = b;
  return true;
}

template<typename A, typename B>
bool chmax(A &a, const B b) {
  if (a >= b) return false;
  a = b;
  return true;
}

#ifndef LOCAL
#define debug(...) ;
#else
#define debug(...) cerr << __LINE__ << " : " << #__VA_ARGS__ << " = " << _tostr(__VA_ARGS__) << endl;

template<typename T>
ostream &operator<<(ostream &out, const vector<T> &v);

template<typename T1, typename T2>
ostream &operator<<(ostream &out, const pair<T1, T2> &p) {
  out << "{" << p.first << ", " << p.second << "}";
  return out;
}

template<typename T>
ostream &operator<<(ostream &out, const vector<T> &v) {
  out << '{';
  for (const T &item : v) out << item << ", ";
  out << "\b\b}";
  return out;
}

void _tostr_rec(ostringstream &oss) {
  oss << "\b\b \b";
}

template<typename Head, typename... Tail>
void _tostr_rec(ostringstream &oss, Head &&head, Tail &&...tail) {
  oss << head << ", ";
  _tostr_rec(oss, forward<Tail>(tail)...);
}

template<typename... T>
string _tostr(T &&...args) {
  ostringstream oss;
  int size = sizeof...(args);
  if (size > 1) oss << "{";
  _tostr_rec(oss, forward<T>(args)...);
  if (size > 1) oss << "}";
  return oss.str();
}
#endif

constexpr int mod = 1'000'000'007; //1e9+7(prime number)
constexpr int INF = 1'000'000'000; //1e9
constexpr ll LLINF = 2'000'000'000'000'000'000LL; //2e18
constexpr int SIZE = 300010;

int A[SIZE];
int counter[SIZE];

int main() {
  int N, K;

  scanf("%d%d", &N, &K);

  for (int i = 0; i < N; i++) {
    scanf("%d", A + i);
    counter[A[i]]++;
  }

  int now = K, prev;
  ll ans = 0;

  for (int i = 0; i <= N; i++) {
    prev = now;
    chmin(now, counter[i]);
    ans += (prev - now) * i;
  }

  cout << ans << endl;

  return 0;
}
#include<iostream>
#include<vector>
#include<algorithm>
#include<set>
#include<map>
#include<queue>
#include<cmath>
#include<iomanip>
#include<cstring>
#include<complex>
#include<cstdio>
#define initdp(a,b) for(int i=0;i<=a;i++)for(int j=0;j<=b;j++)dp[i][j]=-1;
#define fi first
#define se second
#define pb push_back
#define pii pair<int,int>
#define ppi pair<pii,int>
#define pip pair<int,pii>
#define ll long long
#define pll pair<ll,ll>
#define rep(i,n) for(int i=0;i<n;i++)
#define repd(i,n) for(int i=n-1;i>=0;i--)
#define inf 1000000001
#define inf1 1000000000000000001
#define mod 1000000007
#define pie 3.14159265358979323846
#define N 1000005
#define mid(l,r) l+(r-l)/2
#define removeduplicates(vec) vec.erase( unique( vec.begin(), vec.end() ), vec.end() )
using namespace std;
int dx[4]={1,0,-1,0},dy[4]={0,1,0,-1};
int ddx[8]={1,1,0,-1,-1,-1,0,1},ddy[8]={0,1,1,1,0,-1,-1,-1};
void mad(ll &a,ll b){a=(a+b)%mod;if(a<0)a+=mod;}
ll gcd(ll a,ll b){ if(!a)return b;return gcd(b%a,a);}

void solve(){
	ll n,k;
	cin>>n>>k;
	int a[n];
	int mp[n+1]={0};
	int maxi=0;
	rep(i,n){
		cin>>a[i];
		mp[a[i]]++;
		maxi=max(maxi,a[i]);
	}
	ll ans=0;
	mp[maxi+1]=0;
	for(ll x=0;x<=n;x++){
		ll f=mp[x];
		ll can=min(f,k);
		ans+=(k-can)*x;
		k=can;
	}
	cout<<ans;
}
int32_t main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	int t=1;
	//cin>>t;
	while(t--){
		solve();
	}
}