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);
		String str=sc.nextLine();
		String[] s=str.split("");
		int[] X =new int[s.length];
		int cnt=0;
		for(int i=0;i<s.length;i++){
			X[i]=Integer.parseInt(s[i]);
			cnt=cnt+X[i];

		}
		int waru=1;
		for(int i=0;i<s.length-1;i++){
			waru=waru*10;
		}
		
			if(s.length>1 && Integer.parseInt(str)%waru==0){
				cnt=cnt+9;
			}		
		
		System.out.println(cnt);
	}
}
