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
#include <iostream>
using namespace std;

int main() {
  int N;
  cin >> N;

  int ans = 0;
  if (!(N % 10)) ans = 10;
  else {
    while (N > 0) {
      ans += N % 10;
      N /= 10;
    }
  }

  cout << ans << endl;

  return 0;
}
