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

OXdSmcKG, XbDdSmJl
dSm

oGaGjsaKsUpLQAg, iDGjsaKsUoYGuta
GjsaKsU

TaVzwFGeXrKd, DRwFGeedK

wFGe