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

Q: SJIkEibGrqcrOBgGjYjJc, EervOGrqcrOBgGJZyx

A: GrqcrOBgG
****
Q: tftBHoDOYxCoTHVf, qhHoDOYxfUU

A: HoDOYx
****
Q: XWiCPD, OJiClz

A:
iC
****