#include <bits/stdc++.h>
//#include <atcoder/all>
//using namespace atcoder;
using namespace std;
const int INF = 1e9;
using ll = long long;
using ull = unsigned long long;
using inv = vector<int>;
using stv = vector<string>;
using pint = pair<int,int>;
#define FOR(i,l,r) for(int i=(l); i<(r); i++)
#define rep(i,r) for(int i=0; i<(r); i++)
#define repl(i,r) for(long long i=0; i<(r); i++)
#define FORl(i,l,r) for(long long i=(l); i<(r); i++)
#define INFL ((1LL<<62)-(1LL<<31))
#define pb(x) push_back(x)

int main(){
  int N,K;
  cin >> N >> K;
  inv C(N,0);

  inv A(N);
  rep(i,N) cin >> A[i];

  rep(i,N) C[A[i]-1]++;

  sort(C.begin(),C.end(),greater<int>());
  // for(auto c: C) cout << c << " ";
  // cout << endl;
  int ans = 0;

  rep(i,N){
    K -= C[i];
    ans++;
    if(K <= 0){
      break;
    }
  }
  cout << ans << endl;
  return 0;

}