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 Rust (1.15.1) (judge verdict: Accepted)

fn echo() -> Result<&'static str, &'static str> {
    let mut input = String::new();
    std::io::stdin().read_line(&mut input)
        .map_err(|_| "read error")?;
    let n = input.trim_right().parse::<usize>()
        .map_err(|_| "parse error")?;
    let mut input = String::new();
    std::io::stdin().read_line(&mut input)
        .map_err(|_| "read error")?;

    if n % 2 != 0 {
        return Ok("No");
    }

    let mut head = input.chars().take(n / 2);
    let mut tail = input.chars().skip(n / 2);

    for (h, t) in head.zip(tail) {
        if h != t {
            return Ok("No");
        }
    }
    Ok("Yes")
}

fn main() {
    println!("{}", echo().unwrap());
}