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;

public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int a = 1,b = n - a;
        int min = Integer.MAX_VALUE;
        while (a <= b){
            char[] acr = String.valueOf(a).toCharArray();
            char[] bcr = String.valueOf(b).toCharArray();
            int t = 0;
            for (char ac:acr){
                t += Integer.valueOf(String.valueOf(ac));
            }
            for (char bc:bcr){
                t += Integer.valueOf(String.valueOf(bc));
            }
            min = min > t ? t : min;
            ++a;
            --b;
        }
        System.out.println(min);
    }
}
