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 B = 0;
    int min = Integer.MAX_VALUE;
    
    for(int i = 1; i<N; i++){
      A=i;
      B=N-i;
      
      int sum = 0;
      while(A>0){
        sum += A%10;
        A /= 10;
      }
      while(B>0){
        sum += B%10;
        B /= 10;
      }
      min = Math.min(min, sum);
    }
    
    System.out.println(min);
  }
}
        
    
    
    