import sys
input = sys.stdin.readline
from collections import defaultdict
n,k=map(int,input().split())
a=list(map(int,input().split()))
dic=defaultdict(int)
for i in a:
  dic[i]+=1
l=[]
for i in dic:
  l.append(dic[i])
l.sort(reverse=True)
now=0
idx=0
while now<k:
  now+=l[idx]
  idx+=1
print(idx)