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.*;

class Main
{
    public static void main (String[] args)
    {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int ans = Integer.MAX_VALUE;
        for(int i = 1; i < N; i++){
            ans = Math.min(ans, calc(i) + calc(N - i));
        }
        System.out.println(ans);
    }
    public static int calc(int i)
    {
        if(i == 0){
            return 0;
        }
        return i % 10 + calc((i - i % 10) / 10);
    }
}