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);
        // 整数の入力
        int N = sc.nextInt();

        int result = 0;
        for (int i = 0; i < 6; i++) {
            result += N % 10;
            N = (N - (N % 10)) / 10;
        }
        if (result == 1) result = 10;
        System.out.println(result);
    }
}
