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

SOLUTION: jOPp

PROBLEM: PGjDRPDzGaBR, rpIJRPDzWi

SOLUTION: RPDz

PROBLEM: ZkKsRQlSrhWBfkAKZVmum, KNyNYwlSrhWBfkAnlYtE

SOLUTION:
lSrhWBfkA