import Control.Monad
import Control.Applicative
import Data.Functor
import Data.Function
import Data.Monoid
import Data.Maybe
import Data.List
import Data.Foldable (foldMap)
import Data.List.Split
import Data.Char
import Data.Ratio
import Data.Ord
import Data.Array.IO
 
readInt = read :: String -> Int
readDouble = read :: String -> Double
getInt = readLn :: IO Int
getInts = map readInt . words <$> getLine
sjoin :: (Show a) => [a] -> String
sjoin = unwords . map show
cond :: a -> a -> Bool -> a
cond t f c = if c then t else f
applyBin :: (b -> c -> d) -> (a -> b) -> (a -> c) -> a -> d
applyBin op f g x = op (f x) $ g x
applyUni :: (a -> b -> c) -> (a -> b) -> a -> c
applyUni op f x = op x $ f x
-- end of templete


main = length . filter (applyUni (==) reverse) . lines <$> getContents >>= print