In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.

Input: Consider Input: YWNPkA, LuNPnN

Output: NP


Input: Consider Input: OyrqfQQnzOFUzrkDM, iBkQQnzOFewhjvO

Output: QQnzOF


Input: Consider Input: IgWCrxlTpisJPLr, DbCrxlTpqM


Output: CrxlTp