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
#include<iostream>
using namespace std;

int sep(int n)
{	
	int sum=0;

	if(n % 10 == 0)
		return sum=10;	
	while(n > 0){
		sum += n % 10;
		n /= 10;
	}
	return sum;
}
int main()
{
	int n;
	cin >> n;

	cout << sep(n) << endl;
} 

