instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
ZhHtTXaUmsQfUMNrnt, KvvebSXaUmsQfBspwM
answer:
XaUmsQf


question:
CzkPtkpMTDeNZwCPbJJn, HzpMVDeNZwCPbJVOU
answer:
DeNZwCPbJ


question:
DrUHEEzjQufrmZHOwXHiGNEksY, PwFoXnzjQufrmZHObwAnaDAeiL
answer:

zjQufrmZHO