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

Ex Input:
jeQzwP, kSQzxq

Ex Output:
Qz


Ex Input:
oWwqraAz, uxTqraonu

Ex Output:
qra


Ex Input:
HQJjanpDsRnpfgCfo, yesbsutppDsRnpfgCMniaE

Ex Output:

pDsRnpfgC