{-# LANGUAGE OverloadedStrings #-}

import Data.Bool (bool)

main :: IO ()
main = getLine >> solve <$> getLine >>= putStrLn

solve :: String -> String
solve = bool "NotFound" "Found" . (== 3) . foldl f 0
  where
    f s c
      | s == 0 && c == '4' = 1
      | s == 0 = 0
      | s == 1 && c == '0' = 2
      | s == 1 && c == '4' = 1
      | s == 1 = 0
      | s == 2 && c == '4' = 3
      | s == 2 = 0
      | s == 3 = 3