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

int main()
{
    int n , s = 0 ;
    cin>>n;
    
	while( n > 0 )
	{
	    s += n % 10 ;
	    n /= 10;
	}
	
	if ( s==1 )
	{
	    cout<<10<<endl;
	}
	else 
	{
	    cout<<s<<endl;
	}
}
### Prompt

Generate 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()
{
    int n , s = 0 ;
    cin>>n;
    
	while( n > 0 )
	{
	    s += n % 10 ;
	    n /= 10;
	}
	
	if ( s==1 )
	{
	    cout<<10<<endl;
	}
	else 
	{
	    cout<<s<<endl;
	}
}
```