A14442 | Alphabetical Strings

A string $s$ of length $n$ ( $1 \le n \le 26$ ) is called alphabetical if it can be obtained using the following algorithm:

- first, write an empty string to $s$ (i.e. perform the assignment $s$ := "");
- then perform the next step $n$ times;
- at the $i$ -th step take $i$ -th lowercase letter of the Latin alphabet and write it either to the left of the string $s$ or to the right of the string $s$ (i.e. perform the assignment $s$ := $c+s$ or $s$ := $s+c$ , where $c$ is the $i$ -th letter of the Latin alphabet).

In other words, iterate over the $n$ first letters of the Latin alphabet starting from 'a' and etc. Each time we prepend a letter to the left of the string $s$ or append a letter to the right of the string $s$ . Strings that can be obtained in that way are alphabetical.

For example, the following strings are alphabetical: "a", "ba", "ab", "bac" and "ihfcbadeg". The following strings are not alphabetical: "z", "aa", "ca", "acb", "xyz" and "ddcba".

From the given string, determine if it is alphabetical.

The first line contains one integer $t$ ( $1 \le t \le 10^4$ ) — the number of test cases. Then $t$ test cases follow.

Each test case is written on a separate line that contains one string $s$ . String $s$ consists of lowercase letters of the Latin alphabet and has a length between $1$ and $26$ , inclusive.

Output $t$ lines, each of them must contain the answer to the corresponding test case. Output YES if the given string $s$ is alphabetical and NO otherwise.

You can output YES and NO in any case (for example, strings yEs, yes, Yes and YES will be recognized as a positive answer).