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,a;
    cin >> n;
    a = n %10 + (n/10)%10 + (n/100)%10 +(n/1000)%10 + n/10000;
    if(a==1) cout << 10 << endl;
    else cout << a << endl;
}
