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 = sc.nextInt();

        int rem = N % 10;
        int div = N / 10;
        if(rem == 0){
        	if(N >= 100){
        		while(div >= 100){
        			div /= 10;
        		}
        	}else{
        		div = N;
        	}
    		System.out.println(div);
        }else{
        	while(div >= 10){
            	rem += div % 10;
            	div /= 10;
        	}
    		System.out.println(div + rem);
		}
    }
}