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 main()
{
	int n;
	cin >> n;
	int sum = 0;
	for (int i = 0; i < 8; i++)
	{
		sum += n - (n / 10) * 10;
		n = n / 10;
	}
	cout << (sum == 1 ? 10 : sum) << endl;
}