instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
pySBCdpe, AEBCdOR
answer:
BCd


question:
FiKGCRXutEOzMqP, xdxRXutEsl
answer:
RXutE


question:
tzBrYJkUEymldjBLG, OykkUEymldoh
answer:

kUEymld


