n,k=map(int,input().split())
l=list(map(int,input().split()))
from collections import defaultdict
d=defaultdict(int)

for i in range(n):
    d[l[i]]+=1

ans=[]
for k,v in d.items():
    ans.append((k,v))

ans.sort(key=lambda x: -x[1])

cnt=0
while k>0:
    k-= ans[cnt][1]
    cnt+=1
else:
    print(cnt)