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

Q: ChKUlYUTQQBjZMZkgEed, lmQQBjZMZkgdEf

A: QQBjZMZkg
****
Q: rPPfxUdowLLdvwRtY, PuHovApkfxUdowLLBOhq

A: fxUdowLL
****
Q: hSWqVlHaoiG, fUIgVlHacOok

A:
VlHa
****