Double golf

Task
Solvers

Statement	You are given string S contains only '[', ']' and 'o'. Repeat twice a string surrounded by parentheses. Parentheses can be wrapped so you may have to expand recursively. Constraints * 1 ≤ \|S\| ≤ 15 * Parentheses matches validly Explanation for sample "oo[o[oo][[]o]]o" ↓ "oo[ooooo[[]o]]o" ↓ "oo[ooooo[o]]o" ↓ "oo[ooooooo]o" ↓ "ooooooooooooooooo"
Sample Input
Sample Output

Statement

You are given string S contains only '[', ']' and 'o'.
Repeat twice a string surrounded by parentheses.
Parentheses can be wrapped so you may have to expand recursively.

Constraints
* 1 ≤ |S| ≤ 15
* Parentheses matches validly

Explanation for sample
"oo[o[oo][[]o]]o"
↓
"oo[ooooo[[]o]]o"
↓
"oo[ooooo[o]]o"
↓
"oo[ooooooo]o"
↓
"ooooooooooooooooo"

Sample Input

Sample Output