from bisect import bisect_left
from collections import defaultdict

N, K = map(int, input().split())
A = list(map(int, input().split()))

cnt = defaultdict(int)
for a in A:
    cnt[a] += 1

compress = []
for a in set(A):
    compress.append(cnt[a])
compress.sort(reverse=True)
cumsum = [0]
for a in compress:
    cumsum.append(cumsum[-1] + a)

for i, a in enumerate(cumsum[1:], 1):
    if K <= a:
        print(i)
        exit()