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 (Clang 3.8.0) (judge verdict: Wrong Answer)

#include <cstdio>
#include <cstring>

using namespace std;

int main()
{
    char str1[105],str2[105];
    int n,x,y,flag;
    char* t1=str1;
    char* t2=str2;
    while(~scanf("%d",&n))
    {
        scanf("%s%s",str1,str2);
        y=0,flag=0;
        for(x=0;x<n&&flag==0;x++)
        {
            flag=1,y=0;
            while(flag&&y<n-x)
            {
                if(str1[x+y]!=str2[y])
                    flag=0;
                y++;
            }
        }
        if(x==n)
            printf("%d\n",n+x);
        else
            printf("%d\n",n+x-1);

    }
    return 0;
}