Codeforces Round 932 (Div. 2)
A
Entertainment in MAC
Codeforces
800
原题
←B →
翻译中…

Congratulations, you have been accepted to the Master's Assistance Center! However, you were extremely bored in class and got tired of doing nothing, so you came up with a game for yourself.

翻译中…

You are given a string $s$ and an even integer $n$. There are two types of operations that you can apply to it:

翻译中…
  1. Add the reversed string $s$ to the end of the string $s$ (for example, if $s = $ cpm, then after applying the operation $s = $ cpmmpc).
  2. Reverse the current string $s$ (for example, if $s = $ cpm, then after applying the operation $s = $ mpc).
翻译中…

It is required to determine the lexicographically smallest$^{\dagger}$ string that can be obtained after applying exactly $n$ operations. Note that you can apply operations of different types in any order, but you must apply exactly $n$ operations in total.

翻译中…

$^{\dagger}$A string $a$ is lexicographically smaller than a string $b$ if and only if one of the following holds:

翻译中…
  • $a$ is a prefix of $b$, but $a \ne b$;
  • in the first position where $a$ and $b$ differ, the string $a$ has a letter that appears earlier in the alphabet than the corresponding letter in $b$.
翻译中…

Input

翻译中…

Each test consists of multiple test cases. The first line contains a single integer $t$ ($1 \leq t \leq 500$) — the number of test cases. The description of the test cases follows.

翻译中…

The first line of each test case contains a single even integer $n$ ($2 \leq n \leq 10^9$) — the number of operations applied to the string $s$.

翻译中…

The second line of each test case contains a single string $s$ ($1 \leq |s| \leq 100$), consisting of lowercase English letters, — the string to which the operations are applied.

翻译中…

Output

翻译中…

For each test case, output a single line — the lexicographically smallest string that can be obtained after applying exactly $n$ operations.

翻译中…

Note

翻译中…

In the first test case, you can apply the operation of the second type (i.e., reverse the string $s$) $4$ times. Then the string $s$ will remain equal to cpm.

翻译中…

In the second test case, you can do the following:

翻译中…
  • Apply the operation of the second type, after which $s$ will become equal to birg.
  • Apply operation of the first type (i.e., add the reversed string $s$ to the end of the string $s$), after which $s$ will become equal to birggrib.
翻译中…

样例

Input #1
5
4
cpm
2
grib
10
kupitimilablodarbuz
1000000000
capybara
6
abacaba
Output #1
cpm
birggrib
kupitimilablodarbuz
arabypaccapybara
abacaba
InputCopy OutputCopy
题目信息
题号
1935A
时间限制
1 s
内存限制
256 MB
标签
构造
字符串

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。