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: Wrong Answer)


object MainKt {
  @JvmStatic fun main(args:Array<String>) {
    val N=readLine()!!.toInt()
    val s=readLine()!!.toString()
    val t=readLine()!!.toString()
    val sl=s.length;
    val tl=t.length;
    val l:Int=arrayOf(sl,tl).min()!!
    var common=0
    for (i in 0..(l-1))
    {
      if (s[sl-1-i]==t[i])
      {
       common++; 
      }
      else{
        break
      }
    }
    println(when{
      s==t -> sl
      N>sl+tl-common ->N
      else -> sl+tl-common
    } )
  }
}