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

AkYuNemHGBEDF, uluNemHGAycbWX
uNemHG

GBTHKtWUzK, ovVNKtWUmVJF
KtWU

XjKWrUMuJAsSDwGpxanvUglwm, GUnCMuJAsSDwGpiH

MuJAsSDwGp