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

Q: QECPAHsg, bUfPAHOWb

A: PAH
****
Q: gWMyioGBRpwcXfr, AOQGBRpwcSccqBE

A: GBRpwc
****
Q: lLxXqKscqizXTO, TqrKscqizutDudo

A:
Kscqiz
****