#include <bits/stdc++.h>

using namespace std;

#ifdef LOCAL
#include "debug.hpp"
#else
#define debug(...) 1
#endif

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n, k;
    cin >> n >> k;
    vector<int> A(n);
    for (int i = 0; i < n; i++) {
        int a;
        cin >> a;
        a--;
        A[a]++;
    }
    priority_queue<int> Q;
    for (int i = 0; i < n; i++) {
        if (A[i] > 0) {
            Q.push(A[i]);
        }
    }
    int ans = 0;
    while (1) {
        int x = Q.top();
        Q.pop();
        k -= x;
        ans++;
        if (k <= 0) {
            cout << ans << '\n';
            return 0;
        }
    }
}