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.*;

import sun.font.TrueTypeFont;

import static java.lang.System.out;

public class Main{
   public static Scanner sc = new Scanner(System.in);
   public static void main(String args[]){
      int N = sc.nextInt();
      int sum = 0;
      while(N > 0) {
        sum += N % 10;
        N /= 10;
      }
      if (sum == 1){
        sum*= 10;
      }
      out.println(sum);
   }
}