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

[Q]: EyvnjbVLF, vqnjblzR
[A]: njb


[Q]: kWnjCoVmCSVuW, RILPKCoVmCSVbaOza
[A]: CoVmCSV


[Q]: zlugCpUKp, ZTgCpQf
[A]:
gCp