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) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc =new Scanner(System.in);
		int n=sc.nextInt();
		int ans=0;
		if(Math.log10(n)%1==0) {
			ans=10;
		}
		else {
			while(n>0) {
				ans+=n%10;
				n=n/10;
			}
		}
		System.out.println(ans);
		
	}
	

}


