Problem:
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

Solution in JavaScript (node.js v5.12) (judge verdict: Accepted)

// 文字の長さ
// 文字列
// 文字列がある文字列の繰り返しで生成されたものかを判断する

"use strict";

main(require("fs").readFileSync("/dev/stdin", "utf-8"));

function main(input) {
  input = input.split("\n");
  const length = parseInt(input.shift());
  let char = input[0].split("");
  let char1 = char.slice(0, length / 2).join("");
  let char2 = char.slice(length / 2, length).join("");
  console.log(char1 === char2 ? "Yes" : "No");
}