N,K=map(int, input().split())
A=list(map(int, input().split()))
D={}
for a in A:
  if a not in D:
    D[a]=0
  D[a]+=1

E=[]
for d in D:
  E.append(D[d])
E=sorted(E)[::-1]
c=0
for i in range(len(E)):
  c+=E[i]
  if c>=K:
    print(i+1)
    exit()