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 Java7 (OpenJDK 1.7.0) (judge verdict: Accepted)

/* Filename: AGC006A.java
 * Author: Mushiyo
 */

import java.util.Scanner;

public class Main{

	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);

		while (input.hasNext()) {
			int N = input.nextInt();
			String s = input.next();
			String t = input.next();
			StringBuilder ans = new StringBuilder(s);
			
			
			for(int i = 0; i < s.length(); ++i){
				boolean isAllMatch = true;
				int j = 0;
				
				for( ; j < t.length() && i + j < s.length(); ++j){
					if(s.charAt(i + j) != t.charAt(j)){
						isAllMatch = false;
						break;
					}
				}
				
				if(isAllMatch){
					ans.append(t.substring(j));
					break;
				}
			}
			
			if(ans.indexOf(t) == -1){
				ans.append(t);
			}
			
			System.out.println(ans.length());
		}
	}

}