instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
fBpRXPkikQokGVeS, FwUbKXkikQokGos
answer:
kikQokG


question:
umXfmRnUgALpFAqBaKfNfo, aOAXWnUgALpFAqBmNpTCdj
answer:
nUgALpFAqB


question:
ahLCRKgFeeSXSEwXUAxYYSixPf, QvLoUoGeeSXSEwXUJlOjkae
answer:

eeSXSEwXU