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>
using namespace std;
long long a,b,c=0,d,e[1000001],f[1000001];
int main(){
	cin>>a;
	b=a;
	while(b>0){
		c+=b%10;
		b/=10;
	}
	if(c==1){
		cout<<10<<endl;
	}
	else{
		cout<<c<<endl;
	}
	return 0;
}