#include <iostream>
#include <string>
using namespace std;
int main() {
  string s;
  cin >> s;
  int d = 0;
  int r;
  for (char c : s) {
    if ('0' <= c && c <= '9') {
      d++;
      r += c - '0';
    }
  }
  cout << max(r, d * 9 + s[0] - '0' - 10) << endl;
  return 0;
}
### Prompt

Create a solution in cpp for the following problem:

Find the maximum possible sum of the digits (in base 10) of a positive integer not greater than N.

Constraints

* 1\leq N \leq 10^{16}
* N is an integer.

Input

Input is given from Standard Input in the following format:


N


Output

Print the maximum possible sum of the digits (in base 10) of a positive integer not greater than N.

Examples

Input

100


Output

18


Input

9995


Output

35


Input

3141592653589793


Output

137

### Response

```cpp
#include <iostream>
#include <string>
using namespace std;
int main() {
  string s;
  cin >> s;
  int d = 0;
  int r;
  for (char c : s) {
    if ('0' <= c && c <= '9') {
      d++;
      r += c - '0';
    }
  }
  cout << max(r, d * 9 + s[0] - '0' - 10) << endl;
  return 0;
}
```