CF1935A.Entertainment in MAC

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题目描述

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.

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

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

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

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

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

输入格式

Each test consists of multiple test cases. The first line contains a single integer tt ( 1t5001 \leq t \leq 500 ) — the number of test cases. The description of the test cases follows.

The first line of each test case contains a single even integer nn ( 2n1092 \leq n \leq 10^9 ) — the number of operations applied to the string ss .

The second line of each test case contains a single string ss ( 1s1001 \leq |s| \leq 100 ), consisting of lowercase English letters, — the string to which the operations are applied.

输出格式

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

输入输出样例

  • 输入#1

    5
    4
    cpm
    2
    grib
    10
    kupitimilablodarbuz
    1000000000
    capybara
    6
    abacaba

    输出#1

    cpm
    birggrib
    kupitimilablodarbuz
    arabypaccapybara
    abacaba

说明/提示

In the first test case, you can apply the operation of the second type (i.e., reverse the string ss ) 44 times. Then the string ss will remain equal to cpm.

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

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