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: Wrong Answer)

import sys
n=input()
s=input()
t=input()
count=0
sub_count=0
max=len(s+t)
for j in range(len(t)):
    for i in range(len(s)):
        if s[i]==t[j]:
            while i<len(s) and j<len(t) and s[i]==t[j]:
                i+=1
                j+=1
                max-=1
            print(max)
            sys.exit()
print(max)