{-# LANGUAGE BangPatterns #-}
import Control.Applicative((<$>))
import Control.Monad
import Data.Map ((!))
import qualified Data.Map as M
import qualified Data.List as L
import Data.Maybe (catMaybes)
-- import qualified Data.Char as C
-- import qualified Data.IntSet as I
import Debug.Trace
-- import Text.Regex.Posix ((=~))
--------------------------------------------
readInt    = read :: String -> Int
getInt     = readInt <$> getLine
getIntList = map readInt . words <$> getLine
int2bin 0 =  []
int2bin n =  n `mod` 2 : int2bin (n `div` 2)
----------------------------------------------

counter ans [] =
  let tmp = length ans in
  if tmp == 3 then "Three" else "Four"
counter ans (s:ss)
  | s == ' ' = counter ans ss
  | any (s ==) ans = counter ans ss
  | otherwise = counter (s:ans) ss

main :: IO ()
main = do
  n  <- getInt
  ss <- getLine
  putStrLn $ counter "" ss
