You are an expert competitive programmer. You will be given a problem statement, test case constraints and example test inputs and outputs. Please reason step by step about the solution (that must respect memory and time limits), then provide a complete implementation in c++17.

Your solution must read input from standard input (cin), write output to standard output (cout).
Do not include any debug prints or additional output.

Put your final solution within a single code block:
```cpp
<your code here>
```

Execution time limit: 1.0 seconds
Memory limit: 256.0 MB

# Problem
You are given two positive integers $$$n$$$ and $$$k$$$.

Your task is to find a string $$$s$$$ such that all possible strings of length $$$n$$$ that can be formed using the first $$$k$$$ lowercase English alphabets occur as a subsequence of $$$s$$$.

If there are multiple answers, print the one with the smallest length. If there are still multiple answers, you may print any of them.

Note: A string $$$a$$$ is called a subsequence of another string $$$b$$$ if $$$a$$$ can be obtained by deleting some (possibly zero) characters from $$$b$$$ without changing the order of the remaining characters.

## Input Format
The first line of input contains a single integer $$$t$$$ ($$$1\leq t\leq 676$$$) denoting the number of test cases.

Each test case consists of a single line of input containing two integers $$$n$$$ ($$$1\leq n\leq 26$$$) and $$$k$$$ ($$$1\leq k\leq 26$$$).

## Output Format
For each test case, print a single line containing a single string $$$s$$$ which satisfies the above property. If there are multiple answers, print the one with the smallest length. If there are still multiple answers, you may print any of them.

## Examples
```input
4
1 2
2 1
2 2
2 3
```
```output
ab
aa
baab
abcbac
```

## Note
For the first test case, there are two strings of length $$$1$$$ which can be formed using the first $$$2$$$ lowercase English alphabets, and they are present in $$$s$$$ as a subsequence as follows:

- $$$\texttt{a}: {\color{red}{\texttt{a}}}\texttt{b}$$$
- $$$\texttt{b}: \texttt{a}{\color{red}{\texttt{b}}}$$$

For the second test case, there is only one string of length $$$2$$$ which can be formed using the first lowercase English alphabet, and it is present in $$$s$$$ as a subsequence as follows:

- $$$\texttt{aa}: {\color{red}{\texttt{aa}}}$$$

For the third test case, there are $$$4$$$ strings of length $$$2$$$ which can be formed using the first $$$2$$$ lowercase English alphabets, and they are present in $$$s$$$ as a subsequence as follows:

- $$$\texttt{aa}: \texttt{b}{\color{red}{\texttt{aa}}}\texttt{b}$$$
- $$$\texttt{ab}: \texttt{ba}{\color{red}{\texttt{ab}}}$$$
- $$$\texttt{ba}: {\color{red}{\texttt{ba}}}\texttt{ab}$$$
- $$$\texttt{bb}: {\color{red}{\texttt{b}}}\texttt{aa}{\color{red}{\texttt{b}}}$$$

For the fourth test case, there are $$$9$$$ strings of length $$$2$$$ which can be formed using the first $$$3$$$ lowercase English alphabets, and they are present in $$$s$$$ as a subsequence as follows:

- $$$\texttt{aa}: {\color{red}{\texttt{a}}}\texttt{bcb}{\color{red}{\texttt{a}}}\texttt{c}$$$
- $$$\texttt{ab}: {\color{red}{\texttt{ab}}}\texttt{cbac}$$$
- $$$\texttt{ac}: \texttt{abcb}{\color{red}{\texttt{ac}}}$$$
- $$$\texttt{ba}: \texttt{abc}{\color{red}{\texttt{ba}}}\texttt{c}$$$
- $$$\texttt{bb}: \texttt{a}{\color{red}{\texttt{b}}}\texttt{c}{\color{red}{\texttt{b}}}\texttt{ac}$$$
- $$$\texttt{bc}: \texttt{a}{\color{red}{\texttt{bc}}}\texttt{bac}$$$
- $$$\texttt{ca}: \texttt{ab}{\color{red}{\texttt{c}}}\texttt{b}{\color{red}{\texttt{a}}}\texttt{c}$$$
- $$$\texttt{cb}: \texttt{ab}{\color{red}{\texttt{cb}}}\texttt{ac}$$$
- $$$\texttt{cc}: \texttt{ab}{\color{red}{\texttt{c}}}\texttt{ba}{\color{red}{\texttt{c}}}$$$

Now solve the problem and return the code.