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

SOLUTION: JAkt

PROBLEM: gfXPLNzsyfEotmHL, oJeXPLNzsyJuXP

SOLUTION: XPLNzsy

PROBLEM: XgdnEqnjsRZtuvEY, GfjsRZtuvwTSAGd

SOLUTION:
jsRZtuv