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 i = 10;
  int total = 0;
  while(N != 0){
    total += (N % i);
    N /= i;
  }
  if(total == 1) total = 10;
  cout << total << endl;
  return 0;
}
