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

inputFormat

Input

Input is given from Standard Input in the following format:

N

outputFormat

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

样例

3141592653589793

137