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 ans = 0;
  
  if(N % 10 != 0){
    for(;N > 0; N /= 10){
      ans += N % 10;
    }
      cout << ans << endl;
    return 0;
  }
  cout << 10 << endl;
}
