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

ilgSzrcUKLTNLJbMKMKSt, hFXIuUKLTNLJbMKWxSCkDjY
UKLTNLJbMK

ZhHtTXaUmsQfUMNrnt, KvvebSXaUmsQfBspwM
XaUmsQf

liAMjTZsnSfqcdVFDog, jPddxRxMjTZsnSfqcLd

MjTZsnSfqc