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

Input: Consider Input: pYmzRnGPQVPrqPApKTyvaO, tNGPQVPrqPVTh

Output: GPQVPrqP


Input: Consider Input: wkVVZREWhcSCpvCTB, ZQWhcSCpvCDVUY

Output: WhcSCpvC


Input: Consider Input: RfSEtr, gdSEVP


Output: SE