#include<bits/stdc++.h>
using namespace std;
int n,ans=4113;
int countmit(int i)
{
	int ret=0;
	while(i)
	{
		ret+=i%10;
		i/=10;
	}
	return ret;
}
int main()
{
	cin>>n;
	for(int i=1;i<n;i++)
		ans=min(ans,countmit(i)+countmit(n-i));
	cout<<ans;
}
### Prompt

Your task is to create 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 n,ans=4113;
int countmit(int i)
{
	int ret=0;
	while(i)
	{
		ret+=i%10;
		i/=10;
	}
	return ret;
}
int main()
{
	cin>>n;
	for(int i=1;i<n;i++)
		ans=min(ans,countmit(i)+countmit(n-i));
	cout<<ans;
}
```