instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
uDaqoOpUtLDdTGTO, ncIgBjDPqoOpUtLDdTNtiEyarDO
answer:
qoOpUtLDdT


question:
ktABEFESAVHZkkY, uMjxiESAVHZkZgWUte
answer:
ESAVHZk


question:
ijeRagTgttviIF, TUaeRagTgtIdbnmA
answer:

eRagTgt