instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
XSnVeAjWLFWTgwmf, WsByLAjWLFWnQfl
answer:
AjWLFW


question:
hGyDyQYdxCCuD, BQiFOyQYdxel
answer:
yQYdx


question:
QOxgtJPAoGHjzuW, jXxTTLtOztJPAoGHjzauctbwwx
answer:

tJPAoGHjz