ANARC09A  Seinfeld
I’m out of stories. For years I’ve been writing stories, some rather silly, just to make simple problems look difficult and complex problems look easy. But, alas, not for this one.
You’re given a non empty string made in its entirety from opening and closing braces. Your task is to find the minimum number of “operations” needed to make the string stable. The definition for being stable is as follows:
 An empty string is stable.
 If S is stable, then {S} is also stable.
 If S and T are both stable, then ST (the concatenation of the two) is also stable.
All of these strings are stable: {}, {}{}, and {{}{}}; But none of these: }{, {{}{, nor {}{.
The only operation allowed on the string is to replace an opening brace with a closing brace, or visaversa.
Input
Your program will be tested on one or more data sets. Each data set is described on a single line. The line is a nonempty string of opening and closing braces and nothing else. No string has more than 2000 braces. All sequences are of even length.
The last line of the input is made of one or more ’’ (minus signs.)
Output
For each test case, print the following line:
k. N
Where k is the test case number (starting at one,) and N is the minimum number of operations needed to convert the given string into a balanced one.
Example
Input: }{
{}{}{}
{{{}

Output: 1. 2
2. 0
3. 1
hide comments
Himanshu:
20140608 10:00:10
my 200th spoj ACCEPTED :) 

agaurav77:
20140525 16:13:38
Simple Enough O(n) solution. Elegance!! 

yagyank:
20140401 21:28:32
Last edit: 20140401 21:33:14 

yagyank:
20140401 21:28:30
Last edit: 20140401 21:32:59 

vishnu:
20140316 19:16:52
Can someone give some more testcases ? 

Rishab Kalra:
20140111 13:22:44
my 150th classical :D 

Mukit09:
20131020 07:13:05
gets() give WA but scanf() is OK !!! :/


Vishal Sharma:
20130806 16:05:53
for runtime sigsev


chk:
20130804 18:16:45
good problem :)


Priya:
20130717 19:37:10
will somebody explain y i m getting runtime error(sigsegv)

Added by:  Mohammad Kotb 
Date:  20091128 
Time limit:  3.236s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ASM64 BASH JSRHINO 
Resource:  http://www.icpcanarc.org 