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

SOLUTION: tWZYd

PROBLEM: HEVqGddewrNqiZ, iyvlddewrNXr

SOLUTION: ddewrN

PROBLEM: kOjaSi, cKjahT

SOLUTION:
ja