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 sc = new Scanner(System.in);
        int N = sc.nextInt();

        int min = Integer.MAX_VALUE;
        for (int i = 1; i < N; i++) {
            int a = i;
            int b = N - i;

            int sum = 0;
            while (a > 0) {
                sum += a % 10;
                a /= 10;
            }

            while (b > 0) {
                sum += b % 10;
                b /= 10;
            }
            min = Math.min(sum, min);
        }
        System.out.println(min);
    }
}
