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 Kotlin (1.0.0) (judge verdict: Accepted)

fun main(args: Array<String>) {
    val N = nextInt()
    val S = next()
    val T = next()
    var n = 0
    while (n < N) {
        var m = N - n
        while (m > 0) {
            if (S.substring(n) == T.substring(0, m)) {
                println(N + N - m)
                return
            }
            m--
        }
        n++
    }
    println(N+n)
}
fun next() = readLine()!!
fun nextInt() = Integer.parseInt(next())