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 Perl (v5.18.2) (judge verdict: Accepted)

#!usr/bin/perl
chomp($len=<>);chomp($_=<>);
$len = ($len % 2) ? 0 : $len/2;
$a = $_;
s/(.{$len})(.{$len})/\2\1/;
if($_ eq $a && $len != 0){print "Yes";}
else{print "No";}