Description: You are given a string $$$s$$$ of length $$$n$$$. Let's define two operations you can apply on the string: - remove the first character of the string; - remove the second character of the string. Your task is to find the number of distinct non-empty strings that can be generated by applying the given operations on the initial string any number of times (possibly zero), in any order. Input Format: Each test consists of multiple test cases. The first line contains a single integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. The description of the test cases follows. The first line of each test case contains $$$n$$$ ($$$1 \leq n \leq 10^5$$$) — the length of the string. The second line of each test case contains the string $$$s$$$. It is guaranteed that the string only contains lowercase letters of the English alphabet. It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$. Output Format: For each test case, output a single integer: the number of distinct non-empty strings you can get. Note: In the first test case, we can get the following strings: $$$a$$$, $$$aa$$$, $$$aaa$$$, $$$aaaa$$$, $$$aaaaa$$$. In the third test case, for example, the word $$$ba$$$ can be reached in the following way: - remove the first character of the current string $$$ababa$$$, getting $$$baba$$$; - remove the second character of the current string $$$baba$$$, getting $$$bba$$$; - remove the second character of the current string $$$bba$$$, getting $$$ba$$$.