#include <bits/stdc++.h>
using namespace std;

int main()
{
  string n; cin >> n;
  int sum = 0;
  for(char c: n)
  {
    int a = c - '0';
    sum += a;
  }
  if (sum == 1)
  {
    cout << 10 << endl;
  }
  else
  {
    cout << sum << endl;
  }
  return 0;
}
### Prompt

Your challenge is to write a Cpp solution to the following problem:

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

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;

int main()
{
  string n; cin >> n;
  int sum = 0;
  for(char c: n)
  {
    int a = c - '0';
    sum += a;
  }
  if (sum == 1)
  {
    cout << 10 << endl;
  }
  else
  {
    cout << sum << endl;
  }
  return 0;
}
```