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
public class Main {
	public static void main(String[] args) {
		java.util.Scanner s = new java.util.Scanner(System.in);
		System.out.println(Main.calc(s.nextInt()));
	}

	public static int calc(int n) {
		int res = n;
		for (int a = 1; a < n; a++) {			
			int b = n - a;
			int cal = Main.calcKeta(a) + Main.calcKeta(b);
			res = Math.min(cal, res);
		}

		return res;
	}

	private static int calcKeta(int n) {
		return (n == 0) ? 0 : n % 10 + Main.calcKeta(n / 10);
	}
}