instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
pIkAtJHVcvzzZVz, btWerNSHVcvzzZTz
answer:
HVcvzzZ


question:
jJSSBmflUyrEMLjSycA, YkmujkSSBmflUyrKKJZ
answer:
SSBmflUyr


question:
JgJzBL, ajJzqv
answer:

Jz