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

SOLUTION: JlgEC

PROBLEM: zfUPUDeKbCMQa, BkAJFJUDeKbCMZmkFu

SOLUTION: UDeKbCM

PROBLEM: nQkxtTdENexCbNijVIIMRG, gDdbDitTdENexCbBRcqG

SOLUTION:
tTdENexCb