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

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