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 <bits/stdc++.h>

using namespace std;

int main()
{
	int n;
	cin >> n;
	int a = n / 100000 + (n / 10000) % 10 + (n / 1000) % 10 + (n / 100) % 10 + (n / 10) % 10 + n % 10;
	cout << (a < 2 ? 10 : a) << endl;
	return 0;
}
