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(){
	string s;
	cin>>s;
	int n=s.length();
	int sum=0;
	for(char x:s){
		sum+=(x-'0');
	}
	if(sum==1){
		sum*=10;
	}
	printf("%d\n",sum);
	return 0;
}