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

SOLUTION: DN

PROBLEM: XWKEpwGRkfCFZGOyZQOoypx, lhQkmVqeRkfCFZGOyugPLqs

SOLUTION: RkfCFZGOy

PROBLEM: WeykMtVwpwLop, CODKZqtVwpwLEyElC

SOLUTION:
tVwpwL