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

Input: Consider Input: mQvintdwLUpClREgxv, rYnoXBtdwLUpClRwxsqX

Output: tdwLUpClR


Input: Consider Input: BmxgSFWBlVX, kGgKrgSFWBlGunFcZ

Output: gSFWBl


Input: Consider Input: frLNDpoSeVlKQjnhQeVmhRuX, HXvVlKQjnhQefSUVb


Output: VlKQjnhQe