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

bUHPpvVtFQNSpUdg, zggEFoKBHPpvVtFQNHXsc
HPpvVtFQN

oHoJrr, YAoJSq
oJ

HiqBmcMGcCBPam, tNWxvWMGcCBPRIJ

MGcCBP