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

[Q]: qQkmYsYN, UhkmYHSy
[A]: kmY


[Q]: zzEhnt, sYEhtc
[A]: Eh


[Q]: xQiuhKVakJuqw, HXcTlNiuhKVanch
[A]:
iuhKVa