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 cnt = 0;
 	while (n) 
      cnt += n%10, n/=10;
  	if (cnt == 1) cnt = 10;
  	cout << cnt << endl;
	return 0;
}