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) {
	input = input.split('\n');
  	let num = input[0];
  	let char = input[1];
  	
	const divide = char.length / 2;
  	let first = char.substr(0, divide);
  	let second = char.substr(divide, divide);
  
  	if (num % 2 !== 0) {console.log('No'); return;};
  	if (first === second) {
    	console.log('Yes');
    } else {
    	console.log('No');
    }
  
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));