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

Input: Consider Input: koIZvrJmfKCO, TBvrtjcWIZvrJmfKRZDOE

Output: IZvrJmfK


Input: Consider Input: CUxfOt, dyxfNp

Output: xf


Input: Consider Input: DiBTkiHpGxTCWpr, AlTkiHpGxJklvFBn


Output: TkiHpGx