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

Let me give you an example: PPdQTlHHTJEe, DydQTlHHVnmlLu
The answer to this example can be: dQTlHH
Here is why: Here, 'dQTlHH' is the longest common substring in both the input strings 'PPdQTlHHTJEe' and 'DydQTlHHVnmlLu'.

OK. solve this:
JSQNaNYUxKYHUl, qXqZPQqaNYUxKYcT
Answer:
aNYUxKY