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 =sc.nextInt();
		int min =Integer.MAX_VALUE;
		for (int a =1;a<=N/2;a++) {
			int b = N-a;
			char c[]= String.valueOf(a).toCharArray();
			char d[]= String.valueOf(b).toCharArray();
			int sum =0;
			for (int i=0;i<c.length;i++) {
				sum +=c[i]-'0';
			}
			for (int i=0;i<d.length;i++) {
				sum +=d[i]-'0';
			}
			if (min>sum) {
				min =sum;
			}
		}
		System.out.println(min);
	}
}