In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.

[EX Q]: edjRAatlaiCmWkpqMh, qDZYVWCDTRAatlaiCmYH
[EX A]: RAatlaiCm

[EX Q]: qczzCr, zDzzUI
[EX A]: zz

[EX Q]: hjUGUdMBo, YCGUdBN
[EX A]:
GUd