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 nn = n;
        if(nn % 10 == 0) {
            nn /= 2;
        }
        char[] ch = Integer.toString(nn).toCharArray();
        int ans = 0;
        for (int i = 0; i < ch.length; i++) {
            int tmp = Integer.parseInt(Character.toString(ch[i]));
            ans += tmp;
        }if(n % 10 == 0) {
            ans *= 2;
        }
        System.out.println(ans);
    }
}