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

cvZfWOwa, xOfWOhZs
fWO

fdinRdwwlntwqzYGhV, ZefonRdwwlntoWQbh
nRdwwlnt

cYKcXIVXVqek, uRQGXIVXYSo

XIVX