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

Input: Consider Input: yRhCObvPZYoKUoQnyaatR, NHzLJYPZYoKUoQnJnIsZxC

Output: PZYoKUoQn


Input: Consider Input: BUvWkxrAvDQG, rHrkxrAkCE

Output: kxrA


Input: Consider Input: DDulSTnpOUHFm, DlGLulSTnpOUcelNaKtD


Output: ulSTnpOU