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

oHoJrr, YAoJSq
oJ

fBpRXPkikQokGVeS, FwUbKXkikQokGos
kikQokG

yqhdKemFcTXDz, WBXVdKemFcVaA

dKemFc