#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep1(i, n) for (int i = 1; i < (int)(n + 1); i++)
using ll = long long;
using P = pair<int, int>;
using Graph = vector<vector<int>>;
using mint = modint998244353;

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

    int n, k;
    cin >> n >> k;
    map<int, int> m;
    rep(i, n){
        int a; cin >> a;
        if(m.count(a)){
            m[a]++;
        }
        else{
            m[a] = 1;
        }
    }

    vector<int> d;
    for(auto itr = m.begin(); itr != m.end(); itr++){
        d.push_back(itr->second);
    }
    sort(d.begin(), d.end());
    reverse(d.begin(), d.end());

    int ans = 0;
    while(k>0){
        k -= d[ans];
        ans++;
    }

    cout << ans << endl;
}