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);
		int N = Integer.parseInt(sc.next());
		sc.close();

		int min = 1000;
		for(int i = 1;i < N;i++) {
			int sum = 0;
			char[] A = String.valueOf(i).toCharArray();
			char[] B = String.valueOf(N - i).toCharArray();
			for(int j = 0;j < A.length;j++) {
				sum += Character.getNumericValue(A[j]);
			}
			for(int j = 0;j < B.length;j++) {
				sum += Character.getNumericValue(B[j]);
			}
			if(sum < min) {
				min = sum;
			}
		}
		System.out.println(min);
	}
}