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 num;
	scanf("%d",&num);
	int resp=0;

	while(num){
		resp = resp +num%10;
		num = num/10;
	}
	if(resp==1){
		printf("10\n");
	}else{
		printf("%d\n",resp);
	}
	

	return 0;
}