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

    if(1 == res)
    {
        res *= 10;
    }

    cout << res << endl;

    return 0;
}
