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

SOLUTION: artcMPhJw

PROBLEM: wbdHVigIkjNkuAmbr, iSgIkjNkQYyn

SOLUTION: gIkjNk

PROBLEM: pDeKfGkIrvcxTJTHyeKJ, XEvpctKfGkIrvcxfJJsdEh

SOLUTION:
KfGkIrvcx