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

SOLUTION: Nsbe

PROBLEM: yITbYie, TlqTbYomH

SOLUTION: TbY

PROBLEM: JCETQzuy, DzETQkxg

SOLUTION:
ETQ