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<bits/stdc++.h>
using namespace std;
int main()
{
  int n;
  cin>>n;
  string s;
  string t;
  cin>>s>>t; 
  
  int ans=0;
  int j=0;
  int flag=0;
  for(int i=0;i<n;i++)
  {
    j=0;
    ans=0;
    if(s[i]==t[j]){
      int p=i;
      ans=0;
      while(p<n && s[p]==t[j])
      {
        ans++;
        p++;
        j++;
      }
      if(p==n)flag=1;
    }
    if(flag)break;
  }
  cout<<(2*n)-ans<<endl;
  return 0;
}