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

Input: Consider Input: DUhUbmfLuOFAQann, kwnzfLuOFAErR

Output: fLuOFA


Input: Consider Input: HaIPcFXLhYDp, AdIPcFXtJdRE

Output: IPcFX


Input: Consider Input: RJNMol, RwNMcK


Output: NM