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.*;
public class Main {
  	public static int ds(int num){
      	int sum = 0;
      	while(num > 0){
          sum += num%10;
          num /= 10;
        }
      	return sum;
    }
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		
      	int n = sc.nextInt();
		int a;
      	int b;
      	int stack;
      	int min = -1;
      
      	for(int i = 1; i <= n/2;i++){
          a = i;
          b = n-i;
          stack = ds(a)+ds(b);
          if(stack < min || min == -1) min = stack;
        }
      
      	System.out.println(min);
	}
}