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 C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include<stdio.h>
#include<tuple>
#include<string>
#include<algorithm>
#include<iostream>
#include<map>
#include<string.h>
#include<vector>
#include<math.h>
#include<stdlib.h>
#include<set>
#include<ctype.h>
using namespace std;

typedef long long ll;
typedef pair<int,int> pii;
typedef pair<double, double> pdd;
typedef tuple<int,int,int> t3;

const int MX = 200005;
const int MM = 924844033;

int main()
{
	int N;
	scanf("%d", &N);
	string A, B;
	cin >> A >> B;

	for(int i = N; i >= 1; i--){
		if( A.substr(N-i, i) == B.substr(0, i)) return !printf("%d\n", 2*N - i);
	}
	printf("%d\n", 2*N);
}