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

nxoXDohHr, WcbkXDohFbJ
XDoh

UldKHMpUYADGfEUGcSon, nPHMpUYADGfEKqHCLPmL
HMpUYADGfE

nXVXIEGP, fkXIEkU

XIE