import Data.List
main::IO()
main =do
  getLine
  xs <-fmap (map (\x->read x::Int) . words) getLine
  let exe cnt []   = cnt
      exe cnt [x]  = cnt+1
      exe cnt (x:ys@(y:xs))
        |x==y      = exe cnt $dropWhile (==x) xs
        |otherwise = exe (cnt+1) ys

  print . exe 0 . sort $xs