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.*;
 
class Main{
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    
    int n = sc.nextInt();
    int total = Integer.MAX_VALUE;
    for(int i=1; i<n; i++){
      int x = sum(i)+sum(n-i);
      if(total > x){
        total = x;
      }
    }
    System.out.println(total);

    sc.close();
  }

  public static int sum(int x){
    int sum = 0;
    while(x > 0){
      sum += x%10;
      x /= 10;
    }
    return sum;
  }
}