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

SOLUTION: EF

PROBLEM: AxRSlkQfWHrdlgQG, iXIOrmlkQfWHTy

SOLUTION: lkQfWH

PROBLEM: axPrcSPqsevNmMTwiSwodpfgyK, NSHbxFBsevNmMTwilp

SOLUTION:
sevNmMTwi

