instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
NTINFnRckGsfLqhSoA, UUONcKKFnRckGsfLqVak
answer:
FnRckGsfLq


question:
VXSNlHzkB, EoNlHCiL
answer:
NlH


question:
sTPSpDbqtWcmWCEqAuDSDlRE, JtdEoEHHpsbqtWcmWCEqlNVMKZqfxW
answer:

bqtWcmWCEq