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);
		// 整数の入力
		int a = sc.nextInt();
		int min = Integer.MAX_VALUE;
		for(int i=1;i<a;i++) {

			int tmpA = i;
			int sum = 0;

			while(tmpA > 0) {
				sum += tmpA%10;
				tmpA = tmpA/10;
			}

			int tmpB = a - i;

			while(tmpB > 0) {
				sum += tmpB%10;
				tmpB = tmpB/10;
			}

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

		}


		System.out.println(min);

	}



}