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

Q: jkGcUm, dxGcSI

A: Gc
****
Q: RwqzMTeLMdPx, qaWtYhqzMTeLMdHbWDT

A: qzMTeLMd
****
Q: AOFvYVROxLKSOYCxYom, YOnIvYVROxLKSOyyMYwpYl

A:
vYVROxLKSO
****