Quantum mechanics and computer science are interested in bra-kets. Today however you, the player, will have to write a function to find if the given parenthesis expression is balanced.
>> balance('(()()())') 1
>> balance('(()()())(') 0
>> balance('(())))()())') 0
>> balance('(((()))((())))') 1
Hint: consider using a stack. Review your basic data structures for ideas.