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 sum = 0; 
    while (n) {
        sum += n % 10; 
        n = n/10; 
    }

    sum == 1 ? cout << 10 : cout << sum; 

}