Bracket all Over

#1

didnt understand the question can anyone help with an example

#2

the problem says that you are given a string s , it’s length m and a number n . You have generate all possible pairs of a and b such that:
a + s + b is a valid sequence of brackets of length exactly n .
For example if you are given s = “))” and n = 6(m = 2 obviously) then you can generate following pairs of a and b to make a+s+b a valid sequence:

“()((” “))” “” // Remeber a and b can be blank also.
“((” “))” “()”
“(((” “))” “)”
“(()(” “))” “”
“((()” “))” “”

Hence, the ans for this testcase is 5. If there is no possible combination then print -1. Pls try the question now