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

Q: vhZuXCsIkQR, YflCuXCsIkLu

A: uXCsIk
****
Q: wkVVZREWhcSCpvCTB, ZQWhcSCpvCDVUY

A: WhcSCpvC
****
Q: wIWeWlyki, VPAeWlsq

A:
eWl
****