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

YCAyruPTTHWhCYaiXfIl, OETdzqAyruPTTHWgS
AyruPTTHW

aeQjEeiWGONmzGimhGiw, RIEeiWGONmOZuVYr
EeiWGONm

PbVNBLqhxNcjWidf, mRbBLqhxNcjIxh

BLqhxNcj