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;
inline int sum_di(int x)
{
	int res=0;
	while(x)
	{
		res+=x%10;
		x/=10;
	}
	return res;
}
int main()
{
	int n, res=999999999;
	cin>>n;
	if(n%10==0)
	{
		cout<<"10";
		return 0;
	}
	cout<<sum_di(n);
	return 0;
}
