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

[EX Q]: xMxyohPBlJIEBqghiMdBQPwq, xsBlJIEBqghlMosK
[EX A]: BlJIEBqgh

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

[EX Q]: EqFZsxMXtqBvPBXIDXg, awPvzXtqBvPBEk
[EX A]:
XtqBvPB