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;
typedef long long LL;

int main(){
	int n,ans=0;
	cin>>n;
	while(n){
		ans+=n%10;
		n/=10;
	}
	if(ans==1) cout<<10;
	else cout<<ans;
	return 0;
}
