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

Q: rPPfxUdowLLdvwRtY, PuHovApkfxUdowLLBOhq

A: fxUdowLL
****
Q: jinzsW, SMnzaW

A: nz
****
Q: ggFCDrTRDQnmvLX, cakSRrTRDQtKDj

A:
rTRDQ
****