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

Ex Input:
JzbEpAquDJFKcNvEWZxVqRV, PFiJlpAquDJFKcNcqOpMeAv

Ex Output:
pAquDJFKcN


Ex Input:
XwBMFIV, SNLBMFZQ

Ex Output:
BMF


Ex Input:
ENNilxHwOhDGFuPRULwVvy, mfbPgwOhDGFuPFyDMu

Ex Output:

wOhDGFuP