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

bUHPpvVtFQNSpUdg, zggEFoKBHPpvVtFQNHXsc
HPpvVtFQN

nWTnWqkLqYTBxT, cSTnWqkLqYwXmxRF
TnWqkLqY

ohDzXOBvgmiZZTMjkqmgP, sXbivgmiZZTyS

vgmiZZT