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

[Q]: NxgzLSzFGa, JvLzLSzsuj
[A]: zLSz


[Q]: plSfJAktMfac, TCjYJAktlt
[A]: JAkt


[Q]: cgTjoKgsP, ByTjoKJC
[A]:
TjoK