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

SOLUTION: caiUPH

PROBLEM: BTvLVMYp, mjOvLVMqYo

SOLUTION: vLVM

PROBLEM: BCaChdcQSWgCYXQR, uaxDkZrtChdcQSWgCeQzFrc

SOLUTION:
ChdcQSWgC