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

Input: Consider Input: QeNePjbLBKbDOuAVTJtXL, xjPVOyPbLBKbDOuDsMSEF

Output: bLBKbDOu


Input: Consider Input: aBlALASwuwTZmy, MdwASwuwIW

Output: ASwuw


Input: Consider Input: ZfCDfPcaiQcQHwplCZXoAlAcUqsn, xURQcQHwplCZXYKnyFBTNu


Output: QcQHwplCZX