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

Ex Input:
pqFpUjQGiofBOjfYkRW, pQMnCFlhFpUjQGiofbc

Ex Output:
FpUjQGiof


Ex Input:
rRmkmETbjzCzZZxihrVdefxfcenJ, ogQtzAgWjKCzZZxihrVdRswMCmngp

Ex Output:
CzZZxihrVd


Ex Input:
CePNZhDFbLXOvG, aBjdaLapPNZhDFbLkfhOpR

Ex Output:

PNZhDFbL