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

[Q]: wXGerDNhSNnCCedyzskswVnh, BfFNhSNnCCedybrUbI
[A]: NhSNnCCedy


[Q]: dlzequypR, Puequqv
[A]: equ


[Q]: FOCUBdKUMbxWRC, PCRsBdKUMMA
[A]:
BdKUM