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.*;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String n = in.nextLine();
        for(int i = 1; i < n.length(); i++) {
            if(n.charAt(i) != '0') {
                int sum = 0;
                for(int j = 0; j < n.length(); j++) {
                    sum += n.charAt(j) - '0';
                }
                System.out.println(sum);
                return;
            }
        }
        if(n.charAt(0) == '1') {
            System.out.println(10);
            return;
        }
        System.out.println(n.charAt(0));
    }
}
