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

Q: IKrQfT, crrQRg

A: rQ
****
Q: cvZfWOwa, xOfWOhZs

A: fWO
****
Q: jOApEYEIwpqN, XajEYEIwMmMrY

A:
EYEIw
****