instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
HSsyZzZLZAAq, MFEZzZLJC
answer:
ZzZL


question:
rRmkmETbjzCzZZxihrVdefxfcenJ, ogQtzAgWjKCzZZxihrVdRswMCmngp
answer:
CzZZxihrVd


question:
JhiznhgmiBJnlNzhY, KbTqeznhgmiBJculpvD
answer:

znhgmiBJ