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;
	int ans=0;
		while(n)
		{
			ans+=n%10;
			n/=10;
		}
		if(ans==1)
		{
			cout<<"10";
			return 0;
		}
		cout<<ans;
		
	
	
	return 0;
}