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

Example Input: txJhzNeBj, qLJhzNesV
Example Output: JhzNe

Example Input: yhhzISsXKEbA, KlPrazISsXKzmrVBG
Example Output: zISsXK

Example Input: fSSCAy, PeSCdp
Example Output:
SC