#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <atcoder/modint>
using namespace std;
using i32 = int;
using u32 = unsigned int;
using i64 = long long;
using u64 = unsigned long long;
#define rep(i,n) for(int i=0; i<(int)(n); i++)
const i64 INF = 1001001001001001001;

using Modint = atcoder::static_modint<998244353>;



int main(){
    i64 N, K; cin >> N >> K;
    vector<i64> C(N+1);
    rep(i,N){
        int a; cin >> a;
        C[a]++;
    }
    sort(C.begin(), C.end());
    reverse(C.begin(), C.end());
    int ans = 0;
    while(K > 0){
        K -= C[ans];
        ans++;
    }
    cout << ans << endl;
    return 0;
}



struct ios_do_not_sync{
    ios_do_not_sync(){
        ios::sync_with_stdio(false);
        cin.tie(nullptr);
    }
} ios_do_not_sync_instance;