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 <bits/stdc++.h>

using namespace std;

int main() {
  int n;

  cin >> n;
  int cont = 0;

  if(n % 10 == 0) cout << 10 << endl;
  else {
    while(n > 0) {
      cont += n % 10;
      n /= 10;
    }
    cout << cont << endl;
  }

  return 0;
}