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 min=n;
    for(int i=1;i<n;i++){
      min=Math.min(calc(i)+calc(n-i),min);
    }
    System.out.println(min);
  }
  static int calc(int a){
    int res=0;
    while(a>0){
      res+=a%10;
      a/=10;
    }
    return res;
  }
}