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

SOLUTION: iZoGXaWdj

PROBLEM: QeNePjbLBKbDOuAVTJtXL, xjPVOyPbLBKbDOuDsMSEF

SOLUTION: bLBKbDOu

PROBLEM: OCCUbG, ubCUZT

SOLUTION:
CU