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>
#include <string>
using namespace std;
int main(){
	string n;
	int a;
	cin>>n;
	for(int i=0;i<n.size();++i){
		a+=(n[i]-48);
	}
	if(a==1){
		cout<<10;
		return 0;
	}
	cout<<a;
	return 0;
}