#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using Graph = vector<vector<int>>;
int main() {
  int N,K; cin >> N >> K;
  map<int,int> dic;
  for(int i = 0; i < N; i++) {
    int a; cin >> a;
    dic[a]++;
  }
  vector<int> a;
  for (const auto& [key, value] : dic) {
   a.push_back(value);
  }
  sort(a.begin(),a.end());
  reverse(a.begin(),a.end());
  int ans = 0;
  int y = 0;
  for(int i = 0; i < a.size();i++){
    ans += a[i];
    y++;
    if(ans >= K) {
      
      break;
    }
  }
  cout << y << endl;
}