instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
YcgVJVACcQE, JsJVACcSz
answer:
JVACc


question:
spUbdWDLWCeqr, vIuHkWDLWCQEPaz
answer:
WDLWC


question:
pZXSBDMSurUStaK, ENQVMSurUSiY
answer:

MSurUS