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 wa(int n){
  return n/10000 + n%10000/1000 + n%1000/100 + n%100/10 + n%10;
}

int main() {
  int N,ans = 10000;
  cin >> N;
  for(int A = 1;A < N;A++)ans = min(ans,wa(A)+wa(N - A));
  cout << ans << endl;
}