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.*;

class Main{
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);

		int n = scan.nextInt();

		int ans = 999999999;

		for(int a = 1; a < n; a++) {
			int b = n-a;
			ans = Math.min(ans,getNumSum(a)+getNumSum(b));
		}

		System.out.println(ans);
	}

	static int getNumSum(int n) {
		char[] input = (""+n).toCharArray();
		int sum = 0;
		for(char c : input) {
			sum += (int)(c-'0');
		}
		return sum;
	}
}
