instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
YKpdeJQhzyYiPoODACUu, mjmnIlCehzyYiPoOzZ
answer:
hzyYiPoO


question:
eJPZzg, lFPZbI
answer:
PZ


question:
qxORcdbDlNQenJDy, BcbDlNQeeCm
answer:

bDlNQe