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

Q: pYmzRnGPQVPrqPApKTyvaO, tNGPQVPrqPVTh

A: GPQVPrqP
****
Q: UIjAMFDuxDDGkfQa, VdsHuxDDGkfZHZZ

A: uxDDGkf
****
Q: RecNOGwSIh, lAmcNOGYGo

A:
cNOG
****