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

Ex Input:
gfDDsblwUryUw, UWaRisblwUTqTM

Ex Output:
sblwU


Ex Input:
YCAyruPTTHWhCYaiXfIl, OETdzqAyruPTTHWgS

Ex Output:
AyruPTTHW


Ex Input:
vAZLkrmAeLTcayroZP, OHsienpqkrmAeLTcaIgzI

Ex Output:

krmAeLTca