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

SOLUTION: pBHsrf

PROBLEM: CxwZWv, mkwZgM

SOLUTION: wZ

PROBLEM: ZGwBaBYdtVBLGenTlIlck, FDvKdgiTLAtVBLGenTlInsREa

SOLUTION:
tVBLGenTlI