#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using ld=long double;
ld pie=3.141592653589793;
ll inf=2000000000000000000;
ll mod=998244353;
int main(){
    ll n,k;
    cin >> n >> k;
    vector<ll>a(n);
    vector<ll>memo(n+1,0);
    for (ll i = 0; i < n; i++)
    {
        cin >> a[i];
        memo[a[i]]+=1;
    }
    vector<ll>x;
    for (ll i = 0; i <= n; i++)
    {
        if (memo[i]>0)
        {
            x.push_back(memo[i]);
        }
    }
    sort(x.begin(),x.end());
    reverse(x.begin(),x.end());
    ll now=0;
    for (ll i = 0; i < x.size(); i++)
    {
        now+=x[i];
        if (now>=k)
        {
            cout << i+1 << endl;
            return 0;
        }
        
    }
    
}