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

yRhCObvPZYoKUoQnyaatR, NHzLJYPZYoKUoQnJnIsZxC
PZYoKUoQn

zgJGhxLU, EwJGhedW
JGh

LJQusBDLmMSGwdiEeegmHQbeg, cfQUMSGwdiEeegir

MSGwdiEeeg