#include<iostream>
#include<vector>
#include<string>
using namespace std;
 
int main(){
	long long n,m=0;
	string s,t;

    cin >> n;
    cin >> s >> t;

    for(long long i = n - 1; i >= 0; i--){
        if(s[n-1 - m] == t[i]){
            m++;
        }
    }

	cout << 2 * n - m << endl;
}
### Prompt

Create a solution in cpp for the following problem:

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.

Examples

Input

3
abc
cde


Output

5


Input

1
a
z


Output

2


Input

4
expr
expr


Output

4

### Response

```cpp
#include<iostream>
#include<vector>
#include<string>
using namespace std;
 
int main(){
	long long n,m=0;
	string s,t;

    cin >> n;
    cin >> s >> t;

    for(long long i = n - 1; i >= 0; i--){
        if(s[n-1 - m] == t[i]){
            m++;
        }
    }

	cout << 2 * n - m << endl;
}
```