You are working on a Django application that stores a large dataset of user records. Each user record has an integer value representing the user's activity score. Your task is to optimize a query that finds the maximum score that is less than or equal to a given threshold T.

The scores are stored in a list arr of size n which is sorted in non-decreasing order. You need to find the maximum score x such that x <= T. If no such score exists, return -1.

Line 1: KaTeX can only parse string typed expression — the number of user records.

Line 2: KaTeX can only parse string typed expression space-separated integers KaTeX can only parse string typed expression sorted in non-decreasing order, representing the activity scores.

Line 3: An integer KaTeX can only parse string typed expression — the threshold value.

Print a single integer — the maximum score less than or equal to KaTeX can only parse string typed expression, or KaTeX can only parse string typed expression if no such score exists.