#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;

int main() {
  int N, K; cin >> N >> K;
  map<int, int> mp;
  for (int i = 0; i < N; i++) {
    int a; cin >> a;
    mp[a]++;
  }
  vector<int> vec;
  for (auto p: mp) {
    vec.push_back(p.second);
  }
  sort(vec.rbegin(), vec.rend());
  int ans = 0, sum = 0, i = 0;
  while (sum < K) {
    sum += vec[i];
    ans++;
    i++;
  }
  cout << ans << endl;
  return 0;
}