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

[EX Q]: jJSSBmflUyrEMLjSycA, YkmujkSSBmflUyrKKJZ
[EX A]: SSBmflUyr

[EX Q]: oZZUNCUHtIiauDxQ, OdindZUNCUHtIiLQmWJJf
[EX A]: ZUNCUHtIi

[EX Q]: FYQhdzdJatDpLGwg, LgzdJatDBqzPiA
[EX A]:
zdJatD