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: Wrong Answer)

package main

import (
	"fmt"
)

func main() {
	var n int
	fmt.Scan(&n)

	var s, t string
	fmt.Scan(&s, &t)

	if s == t {
		fmt.Print(len(s))
	}

	if n == 1 {
		fmt.Print(2)
	}

	for i:=0; i>n; i++ {
		if s[i:n] == t[0:n-i] {
			fmt.Print(n+i)
			return
		}
	}

	cn := s + t
	ans := len(cn)
	fmt.Print(ans)
}