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++ (GCC 9.2.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
#include <vector>
#include <queue>
using namespace std;
typedef long long LL;
#define REP(i,n) for(int i=0;i<n;i++)
#define FOR(i,a,b) for(int i=(a);i<(b);++i)

int main(){
    int N;
    cin >> N;
    string s, t;
    cin >> s;
    cin >> t;

    int ans = 2*N;

    for(int j=0; j<N; j++){
        string s_suf = s.substr(j,N-j);
        string t_pre = t.substr(0,N-j);
        if(s_suf == t_pre){
            ans -= (N-j);
            break;
        }
    }

    cout << ans << endl;
    return 0;


}