#include <bits/stdc++.h>
 
using namespace std;
 
string s,t; int N,ans;
 
int main(){

  cin>>N;

  cin>>s>>t; int j=N-1;

  for(int i=N-1; i>=0; i--){

    if(t[i]!=s[j]) ans++;
    else j--;
  
  }

  cout<<ans+N<<endl;
  
  return 0;
  
 
}
### Prompt

Your task is to create a Cpp solution to 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 <bits/stdc++.h>
 
using namespace std;
 
string s,t; int N,ans;
 
int main(){

  cin>>N;

  cin>>s>>t; int j=N-1;

  for(int i=N-1; i>=0; i--){

    if(t[i]!=s[j]) ans++;
    else j--;
  
  }

  cout<<ans+N<<endl;
  
  return 0;
  
 
}
```