101451: [AtCoder]ABC145 B - Echo

Memory Limit:256 MB Time Limit:2 S
Judge Style:Text Compare Creator:
Submit:0 Solved:0

Description

Score : $200$ points

Problem Statement

Given are a positive integer $N$ and a string $S$ of length $N$ consisting of lowercase English letters.

Determine whether the string is a concatenation of two copies of some string. That is, determine whether there is a string $T$ such that $S = T + T$.

Constraints

  • $1 \leq N \leq 100$
  • $S$ consists of lowercase English letters.
  • $|S| = N$

Input

Input is given from Standard Input in the following format:

$N$
$S$

Output

If $S$ is a concatenation of two copies of some string, print Yes; otherwise, print No.


Sample Input 1

6
abcabc

Sample Output 1

Yes

Let $T = $ abc, and $S = T + T$.


Sample Input 2

6
abcadc

Sample Output 2

No

Sample Input 3

1
z

Sample Output 3

No

Input

题意翻译

给定长度为 $N$ 的字符串 $S$,问是否存在一个子串 $T$,使得 $S=T+T$。是则 `Yes`,否则 `No`。 Translated by @Expecting_Sharing(@_JYqwq_)

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