#include<bits/stdc++.h>
using namespace std;
int main() {
	int N, K;
	cin >> N >> K;
	int cnt = 0;
	map<int, int>m;
	for (int i = 0; i < N; i++) {
		int A;
		cin >> A;
		m[A]++;
	}
	vector<pair<int, int>>A;
	for (auto w : m) {
		A.emplace_back(w.second, w.first);
	}
	sort(A.begin(), A.end(), greater<pair<int, int>>());
	int M = A.size();
	int ans = 0;
	for (int i = 0; i < M + 1; i++) {
		if (K > 0) {
			ans++;
			K -= A[i].first;
		}
		else {
			cout << ans << endl;
			break;
		}
	}
}