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

SOLUTION: JvL

PROBLEM: IIbJjQKWaoGKHGgWPcy, uNoMWaoGKHGqbnjmYQ

SOLUTION: WaoGKHG

PROBLEM: dJtZADVTDv, fGdaADVTtdc

SOLUTION:
ADVT