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

MriFNpGM, yaiFNduk
iFN

rPPfxUdowLLdvwRtY, PuHovApkfxUdowLLBOhq
fxUdowLL

noxzKdYT, HMmxzKdWEC

xzKd