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

fBpRXPkikQokGVeS, FwUbKXkikQokGos
kikQokG

slTUxy, oqTUYa
TU

LSQlTEmPQTDbUK, VjQTEmPQEFZXl

TEmPQ