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]: SJIkEibGrqcrOBgGjYjJc, EervOGrqcrOBgGJZyx
[A]: GrqcrOBgG


[Q]: NPHiSZxTCKlYbnkjAkCv, bkyQuUxTCKlYbnkaWiKlarJ
[A]:
xTCKlYbnk