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 void main(String[] args){
	
	//入力
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		//String S=sc.next();
		int a=0;		//適当に調整
		
		while(N>0){
			a+=N%10;
			N/=10;
		}
		if(a==1){
			a=10;
		}
	
	//出力
		System.out.println(a);
	}
}