from collections import Counter
import sys
from functools import partial
# import pypyjit
# pypyjit.set_param('max_unroll_recursion = -1')

sys.setrecursionlimit(500005)
stdin = sys.stdin

ns = lambda: stdin.readline().strip()
ni = lambda: int(ns())
na = lambda: list(map(int, stdin.readline().split()))
nz = lambda: list(map(lambda x: int(x)-1, stdin.readline().split())) # 遅い
printa = partial(print, sep="\n") # printa(*A) で各要素を改行して出力
mod = 1000000007 # 998244353
inf = 10 ** 18

N, K = na()
A = na()

C = Counter(A)

B = [c for c in C.values()]
B.sort(reverse=True)

agg = 0
for i, b in enumerate(B):
    agg += b
    if agg >= K:
        print(i+1)
        exit()