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

Input: Consider Input: FSwxBJ, iTwxAa

Output: wx


Input: Consider Input: SUueHhzGsanfsalEEc, KygEhzGsanfsapbKKX

Output: hzGsanfsa


Input: Consider Input: upRJbgUuhQaUB, RBUYybgUuhBAIjy


Output: bgUuh