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;
  for(;n>0;n/=10){
    ans += n % 10;
  }
  ans = ((ans-1)? ans:10);
  cout << ans << endl;
}