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;
	cin >> N;
	bool zero=true;
	int ans=0;
	while(N>0){
		if(N%10!=0 && N!=1)zero=false;
		ans+=N%10;
		N/=10;
	}
	if(zero)ans=10;
	cout << ans << endl;
	return 0;
}