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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        try (Scanner sc = new Scanner(System.in);) {
            new Main().solve(sc);
        }
    }

    void solve(Scanner sc) {
        int n = sc.nextInt();
        String s = sc.next();
        String t = sc.next();
        if (s.length() + t.length() <= n) {
            System.out.println(n);
        } else {
            for (int i = 0; i < s.length(); i++) {
                if (t.startsWith(s.substring(i))) {
                    System.out.println(s.length() + i);
                    return;
                }
            }
            System.out.println(s.length() + t.length());
        }
    }
}