#yukicoder391A

'''
やばい回に紛れ込んでしまった 助かるかな
'''
f=lambda:list(map(int,input().split()))
from collections import defaultdict as dd
N,K=f(); A=f(); D=dd(int)
for i in A: D[i]+=1
num=[]
for i in D: num.append(D[i])
num.sort(reverse=True)
ans=0; cnt=0
for i in num:
    ans+=1; cnt+=i
    if cnt>=K: print(ans); break