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

SOLUTION: BCd

PROBLEM: CCzKRbuEAmN, qTLzKRbuhEqq

SOLUTION: zKRbu

PROBLEM: aGPOgAjQb, vxLyPOgAjhZkp

SOLUTION:
POgAj