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

SOLUTION: JVACc

PROBLEM: fdxgzAMP, xrcxgzYW

SOLUTION: xgz

PROBLEM: XTtZTgWR, FwlVtZTggQ

SOLUTION:
tZTg