instruction:
In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
question:
apGMPThLTCw, LvMPThYW
answer:
MPTh


question:
RwduMBkDazrwZP, UPzcwtWMBkDazrAw
answer:
MBkDazr


question:
abhEeA, rwhEoL
answer:

hE