Takahashi has two positive integers A and B.

It is known that A plus B equals N. Find the minimum possible value of "the sum of the digits of A" plus "the sum of the digits of B" (in base 10).

Constraints

* 2 ≤ N ≤ 10^5
* N is an integer.

Input

Input is given from Standard Input in the following format:


N


Output

Print the minimum possible value of "the sum of the digits of A" plus "the sum of the digits of B".

Examples

Input

15


Output

6


Input

100000


Output

10
import java.util.Scanner;
public class Main{
  public static void main(String[] arsgs){
    Scanner sc = new Scanner(System.in);
    int n = Integer.parseInt(sc.next());
    int result = 0;
    if(n%10==0){
      System.out.println(10);
    }
    else{
      while(n != 0){
        result += n%10;
        n = n/10;
      }
      System.out.println(result);
    }
  }
}