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

Input: Consider Input: XeQwOS, OuQwNR

Output: Qw


Input: Consider Input: UiaECWZf, gRyaECWLGRl

Output: aECW


Input: Consider Input: tSagnPyMSqxiSVWxtc, nWyfLrnKagnPyMSqxbyhqKZyS


Output: agnPyMSqx