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)

"use strict";

function Main(input) {
  let lines = input.split('\n');
  let ans = "No"
  if(lines[0]%2 == 1){
  	console.log(ans);
    return;
  }
  let first = lines[1].slice(0 ,lines[0]/2);
  let second = lines[1].slice(lines[0]/2,lines[0]);
  if(first === second){
    ans = "Yes";
  }
  console.log(ans);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));