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>
#define int long long
using namespace std;

signed main() {
int N;
cin >> N;

int ans = 0;
if( N % 10 == 0 ){
cout << 10 << endl;
return 0;
}else{
while( N > 0 ){
ans += N % 10;
N /= 10;
}
}
cout << ans << endl;
}
