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

[Q]: JAfPtjqqUYMD, cpXItjqqFN
[A]: tjqq


[Q]: XwBMFIV, SNLBMFZQ
[A]: BMF


[Q]: SephLbKyiZmrEvu, LFlUiphLbKyiZmvs
[A]:
phLbKyiZm