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 Python (3.4.3) (judge verdict: Accepted)

def resolve():
    '''
    code here
    '''
    N = int(input())
    s = input()
    t = input()

    cnt = 0
    for i in range(N):
        if i == 0:
            if s[-1] == t[0]:
                cnt = 1
        else:
            if s[-1* (i+1):] == t[:(i+1)]:
                cnt = i + 1
    
    print(2*N - cnt)

if __name__ == "__main__":
    resolve()