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

Q: skZGHS, HsZGge

A: ZG
****
Q: XbjDHRCWxdPbhibUKn, SrpuPDHRCWxdPbKPWEXNWbZ

A: DHRCWxdPb
****
Q: XZSIPxGqUUe, cdzjPxGqcA

A:
PxGq
****