Problem:
Score : 200 points

Problem Statement

Snuke is interested in strings that satisfy the following conditions:

The length of the string is at least N.

The first N characters equal to the string s.

The last N characters equal to the string t.

Find the length of the shortest string that satisfies the conditions.

Constraints

1≤N≤100

The lengths of s and t are both N.

s and t consist of lowercase English letters.

Input

The input is given from Standard Input in the following format:

N
s
t

Output

Print the length of the shortest string that satisfies the conditions.

Sample Input 1

3
abc
cde

Sample Output 1

5

The shortest string is abcde.

Sample Input 2

1
a
z

Sample Output 2

2

The shortest string is az.

Sample Input 3

4
expr
expr

Sample Output 3

4

The shortest string is expr.

Solution in Go (1.6) (judge verdict: Accepted)

package main

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

var bufin *bufio.Reader
var bufout *bufio.Writer

func main() {
	bufin = bufio.NewReader(os.Stdin)
	bufout = bufio.NewWriter(os.Stdout)
	defer bufout.Flush()
	var N int
	var S, T string
	fmt.Fscanf(bufin, "%d\n", &N)
	fmt.Fscanf(bufin, "%s\n", &S)
	fmt.Fscanf(bufin, "%s\n", &T)
	if S == T {
		fmt.Fprintf(bufout, "%d\n", N)
		return
	}
	ans := 0
	for i := 0; i < N; i++ {
		OK := true
		for j := 0; j < i; j++ {
			if S[N-i+j] != T[j] {
				OK = false
				break
			}
		}
		if OK {
			ans = 2*N - i
		}
	}
	fmt.Fprintf(bufout, "%d\n", ans)

}