instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
RwduMBkDazrwZP, UPzcwtWMBkDazrAw
answer:
MBkDazr


question:
cjDuPZOHjystHnF, okWVdUDuPZOHjSCaEecP
answer:
DuPZOHj


question:
bNNUCwEupM, yXjcCwEuZusP
answer:

CwEu