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 ans = 10000;
		for(int i = 1; i < n; i++) {
			int a = i, sumA = 0, b = n - i, sumB = 0;
			while(a > 0) {
				sumA += a % 10;
				a /= 10;
			}
			while(b > 0) {
				sumB += b % 10;
				b /= 10;
			}
			ans = Math.min(ans, sumA + sumB);
		}
		System.out.println(ans);
	}
}