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

Ex Input:
trHTzJpm, aCHTzVVA

Ex Output:
HTz


Ex Input:
VRXUhOYfTul, JqZUhOYKq

Ex Output:
UhOY


Ex Input:
GdDJtYilwLZFUfXZcyNvOjCTJIT, lDyYEfgLZFUfXZcyQmKsrO

Ex Output:

LZFUfXZcy