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

[EX Q]: UZbmGVDzIaf, qfHwqGVDzIsd
[EX A]: GVDzI

[EX Q]: DFRoMPNDAzNgtLsEPseOzC, qykyPjDAzNgtLsEPYTsNrJaNK
[EX A]: DAzNgtLsEP

[EX Q]: iZDfEjKZSkPSap, GsDfEjKZHbif
[EX A]:
DfEjKZ