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 sum = sc.nextInt();
		int a = 0;
		String b = String.valueOf(sum);
		if(sum%10 == 0){
			a = 10;
		}else{
			String[] c = b.split("",0);
			int[] d = new int[c.length];
			for(int j = 0; j < c.length; j++){
				d[j] = Integer.parseInt(c[j]);
			}
			for(int i = 0; i < d.length; i++){
				a += d[i];
			}
		}
		System.out.println(a);
	}
}