3804: Regular Bracket Sequence
金币值：2
定数：1
时间限制：2.000 s
内存限制：256 M
正确：0
提交：0
正确率：0.00% 命题人：
题目描述
time limit per test
5 secondsmemory limit per test
256 megabytesinput
standard inputoutput
standard outputA bracket sequence is called regular if it is possible to obtain correct arithmetic expression by inserting characters «+» and «1» into this sequence. For example, sequences «(())()», «()» and «(()(()))» are regular, while «)(», «(()» and «(()))(» are not.
One day Johnny got bracket sequence. He decided to remove some of the brackets from it in order to obtain a regular bracket sequence. What is the maximum length of a regular bracket sequence which can be obtained?
Input
Input consists of a single line with non-empty string of «(» and «)» characters. Its length does not exceed 106.
Output
Output the maximum possible length of a regular bracket sequence.
Examples
Input
(()))(
Output
4
Input
((()())
Output
6