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

from collections import Counter
A_count = Counter(A)

A_count_sorted = sorted(A_count.items(),key = lambda x:x[1],reverse=True)
i = 0
while K >= 1:
    K -= A_count_sorted[i][1]
    i += 1

print(i)