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);
		int n, sum=0;
		n=sc.nextInt();
		while (n >= 1)
		{
			sum += n % 10;
			n /= 10;
		}
		if (sum != 1)
			System.out.print(sum);
		else
			System.out.print(10*sum);
	}
}
