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 Python (3.4.3) (judge verdict: Accepted)

N = int(input())
S = input()
len_S = len(S)
count = 0

if len_S % 2 == 1:
    print('No')

else:
    for i in range(len_S//2):
        if S[i] == S[i+(len_S//2)]:
            count += 1
        else:
            print('No')
            break

    if count == len_S//2:
        print('Yes')