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

[Q]: QECPAHsg, bUfPAHOWb
[A]: PAH


[Q]: bUHPpvVtFQNSpUdg, zggEFoKBHPpvVtFQNHXsc
[A]: HPpvVtFQN


[Q]: ElcbJhAxE, uvfcbJhAlHuz
[A]:
cbJhA