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 n;
int main() {
	cin >> n;
	int s = 0;
	while (n > 0) {
		s += n % 10;
		n /= 10;
	}
	cout << (s == 1 ? 10 : s) << '\n';
	return 0;
}