Task-5

[YakutovDmitriy]

• Actually you can't use itertools in this problem. You have to implement algorithm from discrete math lecture. This is more discrete math hw than python hw.
• Please do not add arguments to function. You can create additional function if you want. E.g:

  
  def correctbracketsequences1(output, openb, close, pairs):
  ....

def correctbracketsequences(n): return correctbracketsequences1('', 0, 0, n)

Or:
```python
def correctbracketsequences(n):
    def correctbracketsequences1(output, openb, close, pairs):
        ....
    return correctbracketsequences1('', 0, 0, n)

• Please do not print object. Put all of them into list and return this list from function. You can implement it in many ways. One of them is the following:

  def correctbracketsequences(n):
  result = []
  def correctbracketsequences1(output, openb, close, pairs):
      if openb == pairs and close == pairs:
          result.append(output)
      ...
  correctbracketsequences1('', 0, 0, n)
  return result