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 min = 100000;   
    int target = 0;
    int sumA = 0;
    int sumB = 0;

    for(int a=1;a<N;a++){
      // aの計算
      target = a;
      sumA = 0;
      while (target>0){
        sumA += target%10;
        target = target/10;
      }
      // bの計算
      target = N-a;
      sumB = 0;
      while (target>0){
        sumB += target%10;
        target = target/10;
      }
      
      if(sumA + sumB < min){
        min = sumA + sumB; 
      }
    }
    System.out.println(min);
  }
}