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

Q: RNYHvcNnbsUdJLvS, PpNnbsUdglWhl

A: NnbsUd
****
Q: nYoRQU, gQoRZQ

A: oR
****
Q: ivHNYUhDhiIGet, syYUhDhiIsksW

A:
YUhDhiI
****