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>
#include <algorithm>
using namespace std;
int main(void){
  int n,s=0;
  cin >> n;
  while (n>0){
    s+=n%10;
    n/=10;
  }
  if (s==1) cout << 10 << endl;
  else cout << s << endl;
  return 0;
}