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

Input: Consider Input: BUvWkxrAvDQG, rHrkxrAkCE

Output: kxrA


Input: Consider Input: UysTOtIRtRorNAFKKYD, icDOtIRtRoropYVaKzJ

Output: OtIRtRor


Input: Consider Input: fcBXluLiBr, rfjMXluLyHJ


Output: XluL