instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
TUAHhdvHIBxogI, LjfGsAHhdvHJcSdNV
answer:
AHhdvH


question:
yjoJzBGdwfOhsceoOpoap, uSLMdBGdwfOhsIQHBijd
answer:
BGdwfOhs


question:
GGuMRTirq, lLMRTifi
answer:

MRTi