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: Wrong Answer)

import sys
sys.setrecursionlimit(10**6)
# input = sys.stdin.readline
ii = lambda: int(input())
mis = lambda: map(int,input().split())
lmis = lambda: list(mis())
INF = float('inf')

def main():
    N=ii()
    S=list(input())
    s1=S[:N//2]
    s2=S[N//2:]
    for i in range(N//2):
        if s1[i]!=s2[i]:
            print('No')
            exit()
    print('Yes')


if __name__ == "__main__":
    main()