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

Q: LeHzcEFc, WFzcExvJ

A: zcE
****
Q: QlJnxO, BLJnCQ

A: Jn
****
Q: qSUgIlMxymvvmqNGsJ, ocAcYIlMxymvvGNG

A:
IlMxymvv
****