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 {
	int T;
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		Main tr = new Main();
		tr.test(sc);
		sc.close();
	}
	
	void test(Scanner sc){
		T = sc.nextInt();
		long out = Long.MAX_VALUE;
		for (int i = 1; i <= T/2; i++) {
			int b=T-i;
			String s = ""+b;
			s = i+s;
			long sum=0;
			for (int j = 0; j < s.length(); j++) {
				sum+=s.charAt(j)-'0';
			}
			out=out>sum?sum:out;
		}
		System.out.println(out);
	}
}
