import Control.Applicative
import Control.Monad
import Data.List
import Data.Char
import Data.Maybe
strToInt s = (read :: String -> Int) s
strToInteger s = (read :: String -> Integer) s
strToDouble s = (read :: String -> Double) s

main :: IO ()
main = do
    -- 文字列の入力
    _ <- getLine
    s <- filter (`elem` ['a'..'z']) <$> getLine
    -- 出力
    putStrLn $ if 'Y' `elem` s then "Four" else "Three"
