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:
BdqUloJanutXoOyfLsuA, NRDloJanutXoOQY
answer:
loJanutXoO


question:
UNmmHFBGJ, zLrmHFTn
answer:

mHF