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

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

[EX Q]: cZSEmdgP, YsSEmEIM
[EX A]: SEm

[EX Q]: vTBODsZexNMJYlw, IFLyPsZexNMREpSoz
[EX A]:
sZexNM