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) {
		new Main().run();
	}

	void run() {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		sc.close();

		if(n%10 == 0) System.out.println(10);
		else {
			String nn = n+"";
			String m[] = nn.split("");
			int ans = 0;
			for(int i=0; i<m.length; i++) {
				ans += Integer.parseInt(m[i]);
			}
			System.out.println(ans);
		}
	}
}