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

SOLUTION: GWd

PROBLEM: oCtWZYdkvZ, pkktWZYdEHMW

SOLUTION: tWZYd

PROBLEM: XlXhaeZcfDSlHhLTpLmlhe, xBDSlHhLTpLmDIBxueaeLw

SOLUTION:
DSlHhLTpLm