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

Input: Consider Input: vSFxjd, AHFxpi

Output: Fx


Input: Consider Input: XpFCxFOgTTNCnQzMnVPV, FMqzdOwgTTNCnQzedorxVPe

Output: gTTNCnQz


Input: Consider Input: ToRbtRbXBgSQuidcLlhjI, RQduCICXBgSQuidvxUrqJCW


Output: XBgSQuid