#include<iostream>
using namespace std;

int main(){
	int n;
	cin >> n;

	int ans = 0;
	while(n > 0){
		ans += n % 10;
		n /= 10;
	}
	
	if(ans == 1) cout << 10 << endl;
	else cout << ans << endl;
}//解説解答参考.
### Prompt

In Cpp, your task is to solve 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<iostream>
using namespace std;

int main(){
	int n;
	cin >> n;

	int ans = 0;
	while(n > 0){
		ans += n % 10;
		n /= 10;
	}
	
	if(ans == 1) cout << 10 << endl;
	else cout << ans << endl;
}//解説解答参考.
```