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

Input: Consider Input: FCKbAgSVgj, wAEAWbAgSVSVwD

Output: bAgSV


Input: Consider Input: aIZIsqL, wxSZIsEnO

Output: ZIs


Input: Consider Input: CIGKbN, sMGKgL


Output: GK