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 Go (1.6) (judge verdict: Accepted)

package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

var sc = func() *bufio.Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	return sc
}()

func getInt() (n int) {
	sc.Scan()
	n, _ = strconv.Atoi(sc.Text())
	return n
}
func getString() string {
	sc.Scan()
	return sc.Text()
}

func main() {
	N := getInt()
	S := getString()

	if n := N / 2; N%2 == 0 {
		for i := 0; i < n; i++ {
			if S[i] != S[i+n] {
				goto OUT
			}
		}
		fmt.Println("Yes")
		return
	}
OUT:
	fmt.Println("No")
}