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

SOLUTION: XPLNzsy

PROBLEM: hGyDyQYdxCCuD, BQiFOyQYdxel

SOLUTION: yQYdx

PROBLEM: MuUtRnfkVgXTVZFM, AeKRnfkVgvkjUv

SOLUTION:
RnfkVg