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)

#!/usr/bin/env python3
import sys, math, fractions, itertools, collections, copy, heapq


def solve(N: int, s: str, t: str):
    if t == s:
        print(N)
        return
    for i in range(1, N+1):
        S = s + t[-i:]
        if S[-N:] == t:
            print(len(S))
            break
    return


# Generated by 1.1.4 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    N = int(next(tokens))  # type: int
    s = next(tokens)  # type: str
    t = next(tokens)  # type: str
    solve(N, s, t)

if __name__ == '__main__':
    main()