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

[Q]: yhhzISsXKEbA, KlPrazISsXKzmrVBG
[A]: zISsXK


[Q]: VTwtMVKmrRvL, WLoVtWtMVKmrDCke
[A]: tMVKmr


[Q]: QogMrdVaN, dmgMrdXJnJ
[A]:
gMrd