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,a=99;
  cin >> N;
  for(int i=1; i<N; i++){
    int e=100000,f=0;
    for(; e!=1; e=e/10){
      f+=i%e/(e/10)+(N-i)%e/(e/10);
    }
    a=min(a,f);
  }
  cout << a << endl;
}