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

Q: BUvWkxrAvDQG, rHrkxrAkCE

A: kxrA
****
Q: yywhNdZQkLSzbOvhluicHA, lfZQkLSzbOvhVC

A: ZQkLSzbOvh
****
Q: XFUdbGco, oHUdbmMZ

A:
Udb
****