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

Input: Consider Input: XWKEpwGRkfCFZGOyZQOoypx, lhQkmVqeRkfCFZGOyugPLqs

Output: RkfCFZGOy


Input: Consider Input: nOfXJySmVaJIindcJavXh, YpJWmVaJIindcJnoxyRvunG

Output: mVaJIindcJ


Input: Consider Input: YwdpCJqu, mvpCJdvG


Output: pCJ