In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.

Q: nXVXIEGP, fkXIEkU

A: XIE
****
Q: DZfOjrQffR, CXOjrQQc

A: OjrQ
****
Q: dBkMXyGoNVxDz, vULykMXyGoNVZbA

A:
kMXyGoNV
****