Score : 200 points
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.
Input is given from Standard Input in the following format:
N S
If S is a concatenation of two copies of some string, print Yes
; otherwise, print No
.
6 abcabc
Yes
Let T = abc
, and S = T + T.
6 abcadc
No
1 z
No