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 PHP (5.6.30) (judge verdict: Accepted)

<?php
  
while ($line = fgets(STDIN)) {
   $stdin[] = trim($line);
}
#$v2 = str_split($stdin[0]);
#$v2 = explode(" ", $stdin[0]);


if($stdin[0] % 2 == 1){
  $ans = "No";
}else{
  
  $split = str_split($stdin[1], $stdin[0] / 2);

  if($split[0] == $split[1]){
    $ans = "Yes";
  }else{
    $ans = "No";
  }
  
}

echo $ans . PHP_EOL;