Please solve the programming task below using a self-contained code snippet in a markdown code block.

You are given a 0-indexed string s of even length n. The string consists of exactly n / 2 opening brackets '[' and n / 2 closing brackets ']'.
A string is called balanced if and only if:

It is the empty string, or
It can be written as AB, where both A and B are balanced strings, or
It can be written as [C], where C is a balanced string.

You may swap the brackets at any two indices any number of times.
Return the minimum number of swaps to make s balanced.
 
Please complete the following python code precisely:
```python
class Solution:
    def minSwaps(self, s: str) -> int:
```