use proconio::input;
fn main() {
    input! {
        n: usize,
        k: usize,
        a: [usize; n],
    }

    let mut counts = vec![0; n + 1];
    (0..n).for_each(|i| counts[a[i]] += 1);
    counts.sort_by(|a, b| b.cmp(a));
    let mut position = 0;
    let mut sum = 0;
    for i in 0..n + 1 {
        sum += counts[position];
        if sum >= k {
            position = i + 1;
            break;
        }
    }

    println!("{}", position);
}