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 = 0;
    int sum = 0;
    int ans = 100000;
    
    for(int i = 1; i <= n/2; i++){
      
        a = n-i;
        String I = String.valueOf(i);
        String A = String.valueOf(a);
        char[] ii = I.toCharArray();
        char[] aa = A.toCharArray();
        for(int j = 0; j < ii.length; j++){
          int itmp = Character.getNumericValue(ii[j]);
          sum += itmp;
        }
        for(int k = 0; k < aa.length; k++){
          int atmp = Character.getNumericValue(aa[k]);
          sum += atmp;
        }
        
        if(sum < ans){
          ans = sum;
        }
      
      sum = 0;
    }
    
    System.out.println(ans);
  }
}