#include <bits/stdc++.h>
#include <iterator>
using namespace std;
#define rep(i, n) for(int i=0; i<n; i++)
#define debug 1
using ll = long long;
using ld = long double;
const int mod = 998244353;
const double pi = atan2(0, -1);
#include <time.h>
#include <chrono>

int main() {
	int N, K;
	cin >> N >> K;
	vector<int> cnt(N);
	rep(i, N) {
		int a;
		cin >> a;
		a--;
		cnt[a]++;
	}

	priority_queue<vector<int>> pq;
	rep(i, N) {
		pq.push({ cnt[i], i });
	}

	int ans = 0;
	int now = 0;
	while (now < K) {
		ans++;
		now += pq.top()[0];
		pq.pop();
	}

	cout << ans << endl;
}