instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
qczzCr, zDzzUI
answer:
zz

question:
MSzHyOuaJILkeY, eUibEHoHyOuaJIhfvXy
answer:
HyOuaJI

question:
qUNSrZImlfAMObCch, foODSrZImlfAMODHbZdodOYT
answer:
SrZImlfAMO