QOJ.ac

QOJ

Time Limit: 1 s Memory Limit: 64 MB Total points: 10

#11844. Brackets [B]

Statistics

By a correct bracketing we mean a string consisting of brackets ( and ), in which the number of opening brackets is equal to the number of closing brackets and each prefix of the string contains at least as many opening brackets, as closing brackets. This way, ()() is a correct bracketing, while ())( is not, because prefix ()) contains more closing brackets than opening brackets.

For a given pair of bracketings of length $ 2n $, we say that the earlier bracketing is the one which has an opening bracket in the first position, where these bracketings differ. Such an ordering is equivalent to lexicographical ordering, assuming that '(' < ')'.

Write a program which:

  • reads from the standard input numbers $ n $ and $ k $,
  • finds lexicographically $ k $-th bracketing of length 2$ n $ (bracketings are numbered starting from one),
  • writes result to the standard output.

Input Format

Input contains exactly two integers $ n $ and $ k $ ($1 ≤ n ≤ 4\,000$, $1 ≤ k ≤ 10^{18}$), separated by a single space.

Output Format

In the first and only line your program should output a bracketing of length $ 2n $, which is the $ k $-th bracketing among all correct bracketings of length $ 2n $. Input data is prepared in such a way that the bracketing your program is supposed to find always exists.

Example

Input

3 2

Output

(()())
About Issues

We understand that our problem archive is not perfect. If you find any issues with the problem, including the statement, scoring configuration, time/memory limits, test cases, etc.

You may use this form to submit an issue regarding the problem. A problem moderator will review your issue and proceed it properly.

STOP! Before you submit an issue, please READ the following guidelines:

  1. This is not a place to publish a discussion, editorial, or requests to debug your code. Your issue will only be visible by you and problem moderators. Other users will not be able to view or reply your issues.
  2. Do not submit duplicated issues. If you have already submitted one, please wait for an moderator to review it. Submitting multiple issues will not speed up the review process and might cause your account to be banned.
  3. Issues must be filed in English or Chinese only.
  4. Be sure your issue is related to this problem. If you need to submit an issue regarding another problem, contest, category, etc., you should submit it to the corresponding page.

Active Issues 0

No issues in this category.

Closed/Resolved Issues 0

No issues in this category.