#include <bits/stdc++.h>
using namespace std;

int main() {
	int N, K;
	cin >> N >> K;
	vector<int> A(N);
	map<int, int> m;
	for (int i = 0; i < N; i++){
		cin >> A[i];
		m[A[i]]++;
	}
	int ans = 0;
	vector<pair<int, int>> p;
	for (auto [x, y] : m){
		p.push_back({y, x});
	}
	sort(p.begin(), p.end());
	while (K > 0){
		ans++;
		K -= p.back().first;
		p.pop_back();
	}
	cout << ans << '\n';
}