Teacher: In this task, you are given two strings A, B. Find the longest common substring in the strings A and B.
Teacher: Now, understand the problem? If you are still confused, see the following example:
PPdQTlHHTJEe, DydQTlHHVnmlLu
Solution: dQTlHH
Reason: Here, 'dQTlHH' is the longest common substring in both the input strings 'PPdQTlHHTJEe' and 'DydQTlHHVnmlLu'.

Now, solve this instance: dQxLKVTSOQHTLpITHLUp, QLifsOQHTLpITHOgYfvO
Student:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
OQHTLpITH