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

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    int n, k;
    cin >> n >> k;

    vector<int> b(n, 0);
    for (int i = 0; i < n; i++) {
        int a;
        cin >> a;
        a--;

        b[a]++;
    }
    sort(b.begin(), b.end(), greater<>());

    int r = 0, t = k;
    for (const auto &c : b) {
        r++;
        t -= c;
        if (t <= 0) break;
    }
    cout << r << endl;

    return 0;
}