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

SOLUTION: BlK

PROBLEM: vytthSjj, XVttthSFAvk

SOLUTION: tthS

PROBLEM: VbRrwZWRvujEMxKrOSM, ALkYWRvujEMxhC

SOLUTION:
WRvujEMx