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);

        final int N = sc.nextInt();

        int n = N;
        int ans = 0;
        for (int i = 0; i <= String.valueOf(N).length(); i++) {
            ans += n % 10;
            n /= 10;
        }

        if (ans == 1 && String.valueOf(N).length() > 1) {
            System.out.println(10);
        } else {
            System.out.println(ans);
        }
    }
}
