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>
#include<cstring>
#include<vector>
#include<cmath>
using namespace std;
typedef long long int LL;
int main(){
	int n;
	int s=0;
	cin>>n;
	for(;n>0;n/=10){
		s+=n%10;
	}
	if(s==1)s=10;
	cout<<s<<endl;
	return 0;
}
