#include <bits/stdc++.h>
using namespace std;
int n, ans = 1e9;

int solve(int p) {
	return p ? solve(p / 10) + p % 10 : 0;
}

int main() {
	scanf("%d", &n);
	for (int i = 1; i < n; ++i)
		ans = min(ans, solve(i) + solve(n - i));
	printf("%d", ans);
}

### Prompt

Please create a solution in CPP to the following problem:

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

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
int n, ans = 1e9;

int solve(int p) {
	return p ? solve(p / 10) + p % 10 : 0;
}

int main() {
	scanf("%d", &n);
	for (int i = 1; i < n; ++i)
		ans = min(ans, solve(i) + solve(n - i));
	printf("%d", ans);
}

```