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

cnt={}
for i in a:
  if i not in cnt:
    cnt[i]=0
  cnt[i]+=1

c=[]
for i in cnt:
  c.append(cnt[i])
c.sort(reverse=True)
res=0
for i in range(len(c)):
  res+=c[i]
  if res>=K:
    print(i+1)
    exit()