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 ans = Integer.MAX_VALUE;
		for (int i = 1; i <= N / 2; i++) {
			int a = i;
			int b = N - i;
			int sum = calcEachDigit(a) + calcEachDigit(b);
			ans = Math.min(ans, sum);

		}
		System.out.println(ans);
		sc.close();
	}

	private static int calcEachDigit(int x) {
		int t = x;
		int sum = 0;
		while (t > 0) {
			sum += t % 10;
			t /= 10;
		}
		return sum;
	}
}