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Brackets sequence

Brackets sequence

Let us define a regular brackets sequence in the following way:

  1. Empty sequence is a regular sequence.
  2. If S is a regular sequence, then (S) and [S] are both regular sequences.
  3. If A and B are regular sequences, then AB is a regular sequence.

For example, all of the following sequences of characters are regular brackets sequences:

(), [], (()), ([]), ()[], ()[()]

And all of the following character sequences are not:

(, [, ), )(, ([)], ([(]

Some sequence of characters (, ), [ and ] are given. You are to find the shortest possible regular brackets sequence, that contains the given character sequence as a subsequence. Here, a string a1a2...an is called a subsequence of the string b1b2...bm, if there exist such indices 1i1 < i2 < ... < inm that aj = bij for all 1jn.


Contains at most 100 brackets (characters (, ), [ and ]) that are situated on a single line without any other characters among them.


Write a single line that contains some regular brackets sequence that has the minimal possible length and contains the given sequence as a subsequence.

Time limit 1 second
Memory limit 122.17 MiB
Input example #1
Output example #1