#include <bits/stdc++.h>
#include <atcoder/all>
 
#define elif else if
#define ll long long
#define vll vector<long long>
#define vec vector
#define embk emplace_back
#define rep(i, n) for (ll i = 0; i < n; i++)
#define rep3(i, n, k) for (ll i = k; i < n; i++)
#define all(a) a.begin(), a.end()
#define YNeos(bool) (bool ? "Yes" : "No")
 
using namespace std;
using namespace atcoder;
const ll INF = 1LL << 60;
const ll mod = 998244353;
const double pi = acos(-1);

int main() {
  ll n, k; cin >> n >> k;
  vll a(n); rep(i, n) cin >> a[i];

  map<ll, ll> mp;
  rep(i, n) {
    mp[a[i]]++;
  }
  vll b(0);
  for (auto p : mp) {
    auto key = p.first;
    auto value = p.second;
    b.embk(value);
  }

  sort(all(b));
  reverse(all(b));

  ll ans = 0;
  for(int i = 0; k > 0; i++) {
    ans++;
    k -= b[i];
  }

  cout << ans << endl;
}