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

[Q]: eMDNXl, ZZDNAa
[A]: DN


[Q]: MSzHyOuaJILkeY, eUibEHoHyOuaJIhfvXy
[A]: HyOuaJI


[Q]: AwwCuRnGeYwp, iaOECuRnGlyq
[A]:
CuRnG