{-# LANGUAGE OverloadedLists     #-}
{-# LANGUAGE OverloadedStrings   #-}
{-# LANGUAGE ScopedTypeVariables #-}

import           Control.Monad
import           Data.IORef
import           Data.Maybe
import qualified Data.Text     as T
import qualified Data.Text.IO  as T
import           GHC.Base
import           System.IO

import qualified Data.Array    as A
import qualified Data.IntMap   as I
import           Data.List
import qualified Data.Map      as M
import qualified Data.Set      as S
import qualified Data.Vector   as V

main :: IO ()
main = hinaArare

hinaArare :: IO ()
hinaArare = do
  n :: Int <- readLn
  ss <- T.getLine
  let ans = length $ nub $ T.unpack $ T.filter (/= ' ') ss
  putStrLn $ case ans of
    1 -> "One"
    2 -> "Two"
    3 -> "Three"
    _ -> "Four"