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

Input: Consider Input: gWMyioGBRpwcXfr, AOQGBRpwcSccqBE

Output: GBRpwc


Input: Consider Input: UtUSmsOI, dCUSmGoQ

Output: USm


Input: Consider Input: nnJHlcxyVQSKTSU, vCdTbwKlcxyVQSKkmva


Output: lcxyVQSK