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

Input: Consider Input: STvKOHq, XMGvKOdyM

Output: vKO


Input: Consider Input: PShMbsbexXGlpBuMMDZZS, sVqGxSexXGlpBxuHXoI

Output: exXGlpB


Input: Consider Input: iWqtiQTKohFEjZUJ, khHzqtiQTKoudhtxM


Output: qtiQTKo