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 n, ans;

int main() {
    cin >> n;
    while (n) {
        ans += n % 10;
        n /= 10;
    }
    cout << (ans == 1 ? 10 : ans) << endl;
}