module Main where
import System
import Text.ParserCombinators.Parsec

close "[" = "]"
close "(" = ")"
close "{" = "}"

openParens = foldl1 (<|>) $ map string ["[", "(", "{"]

closeParens p = string (close p)

emptySequence = return ()

nonEmptySequence = do
	p <- openParens
	parentheses
	closeParens p
	parentheses	

parentheses = nonEmptySequence <|> emptySequence

main = do
	args <- getArgs
	putStrLn (check (args !! 0)) where
		check input = case parse parentheses "stdin" input of
				Left err -> "False: " ++ show err
				Right _  -> "True"