Balanced Parentheses Score

You need to evaluate the score of a sequence of balanced parentheses. Each pair of parentheses '()' contributes a score of 1, and each pair of parentheses that is immediately inside another pair contributes double the score of the outer pair. For instance, '()' has score 1, '(())' has a score of 2, and '(()())' has a score of 3. Input a single line containing a string of parentheses. Output the total score of the sequence. Example Input: (()(())) Example Output: 6