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

Input: Consider Input: spUbdWDLWCeqr, vIuHkWDLWCQEPaz

Output: WDLWC


Input: Consider Input: zmbmQuyNGOe, mUMEmQuyiuS

Output: mQuy


Input: Consider Input: aGfVGLYMbXffngss, uUfBTGLYMbXffnMLBV


Output: GLYMbXffn