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

SOLUTION: aECW

PROBLEM: mQvintdwLUpClREgxv, rYnoXBtdwLUpClRwxsqX

SOLUTION: tdwLUpClR

PROBLEM: FLAxDywMmPEvqkOUiw, ImSaYBKWxDywMmPEvCC

SOLUTION:
xDywMmPEv