github.com/captn3m0/codechef.git

---
{"category_name":"easy","problem_code":"YVSTR","problem_name":"Yalalovichik Strings","languages_supported":{"0":"C","1":"CPP14","2":"JAVA","3":"PYTH","4":"PYTH 3.6","5":"PYPY","6":"CS2","7":"PAS fpc","8":"PAS gpc","9":"RUBY","10":"PHP","11":"GO","12":"NODEJS","13":"HASK","14":"rust","15":"SCALA","16":"swift","17":"D","18":"PERL","19":"FORT","20":"WSPC","21":"ADA","22":"CAML","23":"ICK","24":"BF","25":"ASM","26":"CLPS","27":"PRLG","28":"ICON","29":"SCM qobi","30":"PIKE","31":"ST","32":"NICE","33":"LUA","34":"BASH","35":"NEM","36":"LISP sbcl","37":"LISP clisp","38":"SCM guile","39":"JS","40":"ERL","41":"TCL","42":"kotlin","43":"PERL6","44":"TEXT","45":"SCM chicken","46":"PYP3","47":"CLOJ","48":"COB","49":"FS"},"max_timelimit":1,"source_sizelimit":50000,"problem_author":"deadwing97","problem_tester":null,"date_added":"22-12-2018","tags":{"0":"cook101","1":"deadwing97"},"editorial_url":"https://discuss.codechef.com/problems/YVSTR","time":{"view_start_date":1545589802,"submit_start_date":1545589802,"visible_start_date":1545589802,"end_date":1735669800},"is_direct_submittable":false,"layout":"problem"}
---
<span class="solution-visible-txt">All submissions for this problem are available.</span>###Read problems statements in [Hindi](http://www.codechef.com/download/translated/CK101TST/hindi/YVSTR.pdf), [Mandarin Chinese](http://www.codechef.com/download/translated/CK101TST/mandarin/YVSTR.pdf), [Russian](http://www.codechef.com/download/translated/CK101TST/russian/YVSTR.pdf), [Vietnamese](http://www.codechef.com/download/translated/CK101TST/vietnamese/YVSTR.pdf) and [Bengali](http://www.codechef.com/download/translated/CK101TST/bengali/YVSTR.pdf) as well.

To make Yalalovichik even more satisfied and happy, Jafar decided to invent Yalalovichik strings. A string is called a Yalalovichik string if the set of all of its distinct non-empty substrings is equal to the set of all of its distinct non-empty subsequences. 

You are given a string $S$. You need to find the number of its distinct non-empty substrings which are Yalalovichik strings.

**Note:** A string $A$ is called a subsequence of a string $B$ if $A$ can be formed by erasing some characters (possibly none) from $B$. A string $A$ is called a substring of a string $B$ if it can be formed by erasing some characters (possibly none) from the beginning of $B$ and some (possibly none) from the end of $B$. Two substrings or subsequences are considered different if they are different strings.

### Input
- The first line of the input contains a single integer $T$ denoting the number of test cases. The description of $T$ test cases follows.
- The first line of each test case contains a single integer $N = |S|$.
- The second line contains the string $S$.

### Output
For each test case, print a single line containing one integer — the number of distinct Yalalovichik substrings of $S$.

### Constraints 
- $1 \le T \le 100$
- $1 \le N \le 10^6$
- the sum of $N$ over all test cases does not exceed $2 \cdot 10^6$
- $S$ contains only lowercase English letters

### Example Input
```
1
3
xxx
```

### Example Output
```
3
```

### Explanation
**Example case 1:** The distinct Yalalovichik substrings are "x", "xx" and "xxx".