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.*;

public class Main {
	public static void main(String... args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int cnt = n;
		for (int i = 1 ; i <= n / 2 ; i++) {
			int tmp = cal(i,0) + cal(n-i,0);
			if (cnt > tmp) cnt = tmp;
		}
		System.out.println(cnt);
	}

	private static int cal (int n, int m) {
		if (n <= 9) return n + m;
		else return cal((n - n % 10) / 10 , m + n % 10);
	}
}
