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

[EX Q]: eedZoMwKgDhdsgs, kMMwKgDLm
[EX A]: MwKgD

[EX Q]: RNYHvcNnbsUdJLvS, PpNnbsUdglWhl
[EX A]: NnbsUd

[EX Q]: rSuLPrSZ, xpuLPrPMf
[EX A]:
uLPr