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.*;
public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int a_sum;
    int b_sum;
    int min = 100000000;

    for(int i = 1 ; i < n ; ++i){
      int a = i;
      int b = n-i;
      a_sum = 0;
      b_sum = 0;
      
      while(n>0){
        a_sum += a%10;
        a = (a-a%10)/10;
        if(a==0) break;
      }
      while(n>0){
        b_sum += b%10;
        b = (b-b%10)/10;
        if(b==0) break;
      }
      
      min = Math.min(min,a_sum+b_sum);
      
      
    }

    System.out.println(min);
    
  }
}