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

[Q]: CzkPtkpMTDeNZwCPbJJn, HzpMVDeNZwCPbJVOU
[A]: DeNZwCPbJ


[Q]: BmxgSFWBlVX, kGgKrgSFWBlGunFcZ
[A]: gSFWBl


[Q]: FJhRugtppUYL, szsugtpSam
[A]:
ugtp