Score : $100$ points

问题描述

你将得到一个长度为 $N$ 的字符串 $S$，由小写英文字母组成。
我们将 $S$ 的第 $i$ 个字符记为 $S_i$。
请按照此顺序拼接 $S_1,S_1,S_2,S_2,\dots,S_N$ 和 $S_N$，并输出得到的长度为 $2N$ 的字符串。
例如，若 $S$ 为 beginner，则应输出 bbeeggiinnnneerr。

以上为通义千问 qwen-max 翻译，仅供参考。

Problem Statement

You are given a string $S$ of length $N$ consisting of lowercase English letters.
We denote the $i$-th character of $S$ by $S_i$.
Print the string of length $2N$ obtained by concatenating $S_1,S_1,S_2,S_2,\dots,S_N$, and $S_N$ in this order.
For example, if $S$ is beginner, print bbeeggiinnnneerr.

Constraints

• $N$ is an integer such that $1 \le N \le 50$.
• $S$ is a string of length $N$ consisting of lowercase English letters.

Input

The input is given from Standard Input in the following format:

$N$

$S$

Output

Print the answer.

Sample Input 1

8
beginner

Sample Output 1

bbeeggiinnnneerr

It is the same as the example described in the problem statement.

Sample Input 2

3
aaa

Sample Output 2

aaaaaa

update @ 2024/3/10 08:38:03