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 {
  static Scanner sc = new Scanner(System.in);

  public static void main(String[] args) {
    int N = sc.nextInt();
    int min = Integer.MAX_VALUE;
    for (int i = 1; i < N; i++) {
      int s = count(i) + count(N - i);
      min = Math.min(min, s);
    }
    System.out.println(min);
  }

  static int count(int v) {
    int ret = 0;
    while (v > 0) {
      ret += v % 10;
      v /= 10;
    }
    return ret;
  }

}
