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

jJSSBmflUyrEMLjSycA, YkmujkSSBmflUyrKKJZ
SSBmflUyr

yhhzISsXKEbA, KlPrazISsXKzmrVBG
zISsXK

YlIrvoVebx, nSCIrvoGyJ

Irvo