instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
pqFpUjQGiofBOjfYkRW, pQMnCFlhFpUjQGiofbc
answer:
FpUjQGiof


question:
XpFCxFOgTTNCnQzMnVPV, FMqzdOwgTTNCnQzedorxVPe
answer:
gTTNCnQz


question:
FEimHnRa, mSdimHKN
answer:

imH