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

Input: Consider Input: OXdSmcKG, XbDdSmJl

Output: dSm


Input: Consider Input: JAfPtjqqUYMD, cpXItjqqFN

Output: tjqq


Input: Consider Input: CSQvmblN, ZSvmbSp


Output: vmb