use std::{collections::HashMap, io::Read};

fn main() {
	let mut s = String::new();
	std::io::stdin().read_to_string(&mut s).ok();
	let n: Vec<u64> = s.split_whitespace().flat_map(str::parse).collect();
	let mut h = HashMap::new();
	let (mut a, mut c) = (1, 0);
	for &i in n[2..].iter() {
		*h.entry(i).or_insert(0) += 1;
	}
	let mut v: Vec<_> = h.values().collect();
	v.sort();
	for &d in v.iter().rev() {
		c += d;
		if c >= n[1] {
			break;
		}
		a += 1;
	}
	println!("{a}")
}