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

Ex Input:
JAGuNgaUudP, eojvKNgaUuQg

Ex Output:
NgaUu


Ex Input:
XjYkMfARxWBSBjuXyDrFt, EtUxIfiHkMfARxWBSckTLTTnR

Ex Output:
kMfARxWBS


Ex Input:
lmfCcN, EDfCwU

Ex Output:

fC