#include <bits/stdc++.h>
#include<iostream>
#include<map>
#include<vector>
#include <algorithm>
#include<math.h>
#include <iomanip>
#include<set>
#include <numeric>
#include<string>
using ll = long long;
using namespace std;

int main()
{
    ll n, k;
    cin >> n >> k;
    vector<ll> a(n), b(n);
    for (int i = 0; i < n; i++){
        ll tmp;
        cin >> tmp;
        a[tmp-1]++;
    }
    sort(a.begin(), a.end(), greater());
    for (int i = 0; i < n; i++){
        if (i == 0) b[0] = a[0];
        else b[i] += b[i-1] + a[i];
        if (b[i] >= k) {
            cout << i + 1 << endl;
            return 0;
        }
    }
}