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

[Q]: MriFNpGM, yaiFNduk
[A]: iFN


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


[Q]: fwzFRGleO, OgTCzFRGljUJFg
[A]:
zFRGl