def ri() gets.split.map &:to_i end
N, k=ri
D = {}
for v in ri do
  if not D[v]; D[v]=0 end
  D[v] += 1
end
c = 0
for v in D.each_value.sort.reverse do
  c += 1
  k -= v
  break if k <=0
end
p c