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

SOLUTION: IPcFX

PROBLEM: atDgsOWuP, UJMgsOrwj

SOLUTION: gsO

PROBLEM: TdjCcukuIdZ, zaakBCcukuIZCRvO

SOLUTION:
CcukuI