TASK DEFINITION: In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
PROBLEM: xfZYYDKEqoRRu, ztCeYYDKEqoPG

SOLUTION: YYDKEqo

PROBLEM: STvKOHq, XMGvKOdyM

SOLUTION: vKO

PROBLEM: pySBCdpe, AEBCdOR

SOLUTION:
BCd

