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

[Q]: FSwxBJ, iTwxAa
[A]: wx


[Q]: ykDpbd, YFDpmO
[A]: Dp


[Q]: iTNgJgEOsLUwF, cRwYgJgEOwti
[A]:
gJgEO