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

Input: Consider Input: feYKRk, PrYKMW

Output: YK


Input: Consider Input: jdLbZSCzaAHGbNwILGmudOH, RdIPuEYJvUZSCzaAHGbNduLToRC

Output: ZSCzaAHGbN


Input: Consider Input: mjGZkc, zEGZqW


Output: GZ