#include<bits/stdc++.h>
using namespace std;

char a;
string s;

int main(){
    a = getchar();
    cin >> s;
    for(auto i : s)if(i != 57)return 0 & printf("%lld", s.size() * 9 + a - 49);
    cout << s.size() * 9 + a - 48 << endl;
    return 0;
}
### Prompt

Develop a solution in CPP to the problem described below:

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<bits/stdc++.h>
using namespace std;

char a;
string s;

int main(){
    a = getchar();
    cin >> s;
    for(auto i : s)if(i != 57)return 0 & printf("%lld", s.size() * 9 + a - 49);
    cout << s.size() * 9 + a - 48 << endl;
    return 0;
}
```