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

Ex Input:
elloYaejTczBiiNOU, XoCPzloYaejTcXYtKODL

Ex Output:
loYaejTc

Ex Input:
uGDJixAmSiVaFRmfKRM, NsTGxsJixAmSiVageSw

Ex Output:
JixAmSiVa

Ex Input:
gGqIJC, AkqIWw

Ex Output:
qI