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

SOLUTION: cQOvMB

PROBLEM: STvKOHq, XMGvKOdyM

SOLUTION: vKO

PROBLEM: DQBpdnwVDcnCDEWpD, gAtCdnwVDcnCYv

SOLUTION:
dnwVDcnC