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

Input: Consider Input: PIcbiJj, hedcbiZHF

Output: cbi

Input: Consider Input: nuwMzarLqoPvabJla, JKcrLqoPvabJNDCILGQ

Output: rLqoPvabJ

Input: Consider Input: yzUiRMMtXtYibMZ, WNcuEEiRMMtXtawZi
Output: iRMMtXt