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

SOLUTION: rrwP

PROBLEM: jinzsW, SMnzaW

SOLUTION: nz

PROBLEM: UhOUrViIfWyPCxJm, hLdrViIfWWEpT

SOLUTION:
rViIfW