instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
xzMUdHcoYJFWLOILjrg, vCscoYJFWLzO
answer:
coYJFWL


question:
yywhNdZQkLSzbOvhluicHA, lfZQkLSzbOvhVC
answer:
ZQkLSzbOvh


question:
JHJtdxzFSKjvoefDxIMIskYV, hnGebYpidzFSKjvoefWKMsBbc
answer:

zFSKjvoef