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 sum = 0, d = 1;
  while (d <= n) {
    if (d == n) {
      sum += 10;
    } else {
      sum += (n / d) % 10;
    }
    d *= 10;
  }
  cout << sum << endl;
}