import Control.Monad
import Data.List
main=do
    n<-readLn
    print =<< uni 0.sort<$>replicateM n readLn

uni :: Int -> [Int] -> Int
uni c [] = c
uni c [_] = c+1
uni c (a:b:ds)
    | a == b = uni c (b:ds)
    | True = uni (c+1) (b:ds)