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 n,m,ans,cnt,a[1005];
string s;
int main()
{
	cin>>n; 
    while(n)
    {
    ans+=n%10;
    n/=10;
	}
	if(ans==1)
	ans+=9;
	cout<<ans<<endl;
    return 0;
	} 