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 st[20],tot;
int n;
int main( ){
	int sum=0,digit=0;
	cin>>n;
	int x=n;
	while(x) {
		if(x>10&&x%10) digit=1;
		sum+=x%10;
		x/=10;
	}
	if(!digit&&sum==1) puts("10");
	else cout<<sum<<endl; 
}