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.Scanner;

/**
 *
 * @author Suraj
 */
public class Main {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        Scanner in = new Scanner(System.in);
        int n= in.nextInt();
        String s= Integer.toString(n);
        int l=s.length();
        int p=(int) Math.pow(10, l-1);
        if(p==n){
            System.out.println(10);
        }
        else{
            int sum=0;
            int m;
            while(n > 0)
        {
            m = n % 10;
            sum = sum + m;
            n = n / 10;
        }
            System.out.println(sum);
        }
    }
    
}
