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

Input: Consider Input: rPPfxUdowLLdvwRtY, PuHovApkfxUdowLLBOhq

Output: fxUdowLL

Input: Consider Input: wXGerDNhSNnCCedyzskswVnh, BfFNhSNnCCedybrUbI

Output: NhSNnCCedy

Input: Consider Input: mwfJTXUYAjj, wxeJTXUYUTGnH
Output: JTXUY