Bracket Subsequence

2000ms

262144K

Description:

A bracket sequence is a string containing only characters "(" and ")". A regular bracket sequence is a bracket sequence that can be transformed into a correct arithmetic expression by inserting characters "1" and "+" between the original characters of the sequence. For example, bracket sequences "()()" and "(())" are regular (the resulting expressions are: "(1)+(1)" and "((1+1)+1)"), and ")(", "(" and ")" are not.

Subsequence is a sequence that can be derived from another sequence by deleting some elements without changing the order of the remaining elements.

You are given a regular bracket sequence $$$s$$$ and an integer number $$$k$$$. Your task is to find a regular bracket sequence of length exactly $$$k$$$ such that it is also a subsequence of $$$s$$$.

It is guaranteed that such sequence always exists.

Input:

The first line contains two integers $$$n$$$ and $$$k$$$ ($$$2 \le k \le n \le 2 \cdot 10^5$$$, both $$$n$$$ and $$$k$$$ are even) — the length of $$$s$$$ and the length of the sequence you are asked to find.

The second line is a string $$$s$$$ — regular bracket sequence of length $$$n$$$.

Output:

Print a single string — a regular bracket sequence of length exactly $$$k$$$ such that it is also a subsequence of $$$s$$$.

It is guaranteed that such sequence always exists.

Sample Input:

6 4
()(())

Sample Output:

()()

Sample Input:

8 8
(()(()))

Sample Output:

(()(()))

Informação

Provedor Codeforces

Código CF1023C