# include <iostream>
# include <cstdio>
using namespace std;
long long n,ans;
int main()
{
	scanf("%lld",&n);
	while(n)ans += n % 10LL,n /= 10LL;
	printf("%lld\n",ans == 1 ? 10 : ans);
}
### 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 <iostream>
# include <cstdio>
using namespace std;
long long n,ans;
int main()
{
	scanf("%lld",&n);
	while(n)ans += n % 10LL,n /= 10LL;
	printf("%lld\n",ans == 1 ? 10 : ans);
}
```