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 input = new Scanner(System.in);
        int n = input.nextInt();
        int l = (int) Math.ceil(n/2.0);
        int r = n /2;
        int min = Integer.MAX_VALUE;
        for (int i = l; i > 0 ; i--) {
            min = Math.min(min, getSumDigits(i) + getSumDigits(r));
            r++;
        }
        System.out.println(min);
    }

    public static int getSumDigits(int num){
        int sum = 0;
        while (num > 0) {
            sum = sum + num % 10;
            num = num / 10;
        }

        return  sum;
    }
}
