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
raipavitra:
20200211 06:10:14
apply conditions of stable string as given in problems.


raipavitra:
20200211 06:05:54
here DP doesn't working ,giving TLE. 

chinhvu:
20200115 16:30:44
Good :) 

nagesh_reddy:
20191205 14:27:06
. Last edit: 20191205 14:28:38 

mksingh458:
20190904 22:20:46
THANKS FOR THE strip() in python :) 

shilangyu:
20190824 13:20:58
Remember about `strip()` in python! 

nikhil_sarda:
20190818 06:16:16
Neither DP nor stack require.


sauravraj62:
20190730 00:54:50
Neither DP nor Stack, simple one iteration is enough 

ansul:
20190602 11:21:47
any unusual test case which might cause a wrong answer 

saurav_paul:
20190527 08:56:01
It can easily solve using a stack, but what approach should take to solve using dp?

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 