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>
using namespace std;

int main()
{
    int n;
    cin >> n;
    if(n % 10 == 0) cout << 10;
    else
    {
        int c = 0;
        while(n)
        {
            c += (n%10);
            n /= 10;
        }
        cout << c;
    }
}
