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

[Q]: QlJnxO, BLJnCQ
[A]: Jn


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


[Q]: dQWGkxXEelrzgoPDwzFZITH, MTenEAEelrzgoPDLcCUiCNF
[A]:
EelrzgoPD