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

Input: Consider Input: VRamNL, mUamIB

Output: am


Input: Consider Input: lsNwypFwhKP, diEfLwypFwEKqCN

Output: wypFw


Input: Consider Input: HmApQkFCWTwrEZS, wTZdwXAQkFCWTwTWKQQL


Output: QkFCWTw