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

[Q]: jdLbZSCzaAHGbNwILGmudOH, RdIPuEYJvUZSCzaAHGbNduLToRC
[A]: ZSCzaAHGbN


[Q]: sEYtoQlG, XIstoQQPw
[A]: toQ


[Q]: VIFZnPr, MXFZndTk
[A]:
FZn