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 scan = new Scanner(System.in);

	int N = scan.nextInt();

	int min = Integer.MAX_VALUE;

	for(int i = 1; i < N; i++){
	    int A = i;
	    int B = N-i;
	    int num = 0;
	    while(A > 0){
		num += A%10;
		A /= 10;
	    }
	    while(B > 0){
		num += B%10;
		B /= 10;
	    }

	    if(num < min){
		min = num;
	    }
	}

	System.out.println(min);
    }
}
