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

Ex Input:
HEVqGddewrNqiZ, iyvlddewrNXr

Ex Output:
ddewrN


Ex Input:
HqaOvLaZbs, RifOvLaZkh

Ex Output:
OvLaZ


Ex Input:
umXfmRnUgALpFAqBaKfNfo, aOAXWnUgALpFAqBmNpTCdj

Ex Output:

nUgALpFAqB