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

SOLUTION: chtNymcsw

PROBLEM: HHJAHyvNCGmJEljWrjvHOqf, msPVEbNCGmJEljsKRX

SOLUTION: NCGmJElj

PROBLEM: dSfSeKqevswhlNNb, KLcmvFlqevswhlTRJ

SOLUTION:
qevswhl