p03427 AtCoder Grand Contest 021 - Digit Sum 2
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
```python
N=input()
NL=len(N)
if N[1:]=='9'*(NL-1):
  ans=int(N[0])+9*(NL-1)
else:
  ans=int(N[0])+9*(NL-1)-1
print(ans)
```