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){
		Scanner sc = new Scanner(System.in);

		int n = sc.nextInt();
		String s [] = sc.next().split("");
		String t [] = sc.next().split("");

		int answer = n*2;
		int sum = 0;
		for(int  i = 0;i < n;i++){
			if(s[i].equals(t[0])){
				sum++;
				for(int j = i+1;j < n;j++){
					if(s[j].equals(t[j-i])){
						sum++;
					}else{
						sum = 0;
					}
				}
			}
			if(sum > 0){
				answer -= sum;
				break;
			}
		}

		System.out.println(answer);
	}
}