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 Ruby (2.3.3) (judge verdict: Wrong Answer)

N = gets.to_i

d = gets.chomp.split('')

result = 'No'

i = 0

s = N / 2


if N % 2 == 0
   	while i < s
	   	if d[i] == d[i+s]
	   		i += 1
	   		result = 'Yes'
	   	else
	   		reselt = 'No'
	   		break
	   	end
    end

  else

end

puts result