Compressed Words
Description
Helen has come up with a way to shorten the length of the messages send to their counter parts in the past.  Helen considers only individual words, and uses the following rules to define a "shortened word":

a single, lower-case letter is a compressed word
(e1 e2 ... et n) where t and n are non-negative integers and ei is a compressed word.

You should observe that a compressed word of one character is the same as an uncompressed word. To uncompress the compressed word (e1 e2 ... et n) we uncompress each ei , concatenate those uncompressed words into a new word, and repeatedly concatenate that word n times. For example:

a would be uncompressed as a,
(a 3) would be uncompressed as aaa,
(a (b c d 2) 3) would be uncompressed as abcdbcdabcdbcdabcdbcd.

Write a program to uncompress a compressed word.
Input:
The input consists of one correctly formed compressed word of different lengths on a separate line. Every compressed word in the input is correct according to the rules specified above. Letters and numbers are separated from each other by one space character. Brackets and numbers or letters are separated from each other by at least one space character. One bracket is separated from another by one space character.
Output:
For each test case (each compressed word), write the uncompressed word should be displayed on a new line. There should be no spaces in the output.
 
Input 1:
a
Input 2:
( a 3 )
Input 2:
( a ( b c d 2 ) 3 )
Output 1:
a
Output 2:
aaa
Output 3:
abcdbcdabcdbcdabcdbcd