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 scanner = new Scanner(System.in);
		int N = scanner.nextInt();

		int min = 100;

		for(int i = 1;i<=(N/2);i++) {
			int sum;
			sum = getDigitSum(N-i)+getDigitSum(i);
			if(min>sum) {
				min=sum;
			}
		}

		System.out.println(min);

	}

	private static int getDigitSum(int x) {
		int s =0;
		for(int i = 0;x != 0;i++) {
			s += x%10;
			x /=10;
		}
		return s;
	}

}
