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

SOLUTION: DeNZwCPbJ

PROBLEM: yrIDSuVuQU, UXTSuVuLcch

SOLUTION: SuVu

PROBLEM: yRUubZgQD, ZPeUubZazK

SOLUTION:
UubZ