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

SOLUTION: Yf

PROBLEM: JjEQVKijeyEQ, dwSVKijeywCTvb

SOLUTION: VKijey

PROBLEM: QQMLzRM, pjMLzkmL

SOLUTION:
MLz