This is yet another problem dealing with regular bracket sequences.

We should remind you that a bracket sequence is called regular, if by inserting «+» and «1» into it we can get a correct mathematical expression. For example, sequences «(())()», «()» and «(()(()))» are regular, while «)(», «(()» and «(()))(» are not. 

You are given a string of «(» and «)» characters. You are to find its longest substring that is a regular bracket sequence. You are to find the number of such substrings as well.
The first line of the input file contains a non-empty string, consisting of «(» and «)» characters. Its length does not exceed 10<sup class="upper-index">6</sup>.
def main():
    m = cnt = 1
    stack = [1]
    for c in input():
        if c == '(':
            stack.append(1)
        else:
            try:
                x = stack.pop() + stack.pop() + 1
                if m < x:
                    m = x
                    cnt = 1
                elif m == x:
                    cnt += 1
                stack.append(x)
            except IndexError:
                stack = [1]
    m -= 1
    print(m, cnt if m else 1)


if __name__ == '__main__':
    main()
