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

Input: Consider Input: AxRSlkQfWHrdlgQG, iXIOrmlkQfWHTy

Output: lkQfWH


Input: Consider Input: uDaqoOpUtLDdTGTO, ncIgBjDPqoOpUtLDdTNtiEyarDO

Output: qoOpUtLDdT


Input: Consider Input: RNYHvcNnbsUdJLvS, PpNnbsUdglWhl


Output: NnbsUd