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

Q: fREVIdeTcakgFnwDWTVev, IbtXImseeTcakgFnwDYsKBAlux

A: eTcakgFnwD
****
Q: goyZUz, QryZlD

A: yZ
****
Q: KIKetQsEzSwgrwAlhxnddQ, tdGcEzSwgrwAlaDJtkiFOa

A:
EzSwgrwAl
****