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

Input: Consider Input: vytthSjj, XVttthSFAvk

Output: tthS


Input: Consider Input: YXsgPE, ENsgSO

Output: sg


Input: Consider Input: ZZUygnnUAsqxbKnf, tIgGPRUygnnUAsqEWfVIds


Output: UygnnUAsq