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: jyJrDIhxJtWbnooEXZ, uyXifNCIhxJtWbnVCUrt

A: IhxJtWbn
****
Q: XFzRJvsMpHuXX, hImzRJvsMpcZ

A:
zRJvsMp
****