Problem Statement

When Takahashi writes an integer, he uses a comma every third digit from the right. For example, 1234567 is written as 1,234,567, and 777 is written as 777.
How many commas will be used in total when he writes each integer from 1 through N once?

Input

Input is given from Standard Input in the following format:
N

Output

Print the total number of commas.

Constraints

• $1 \leq N \leq 10^{15}$
• N is an integer.

Sample Input 1

1010

Sample Output 1

11

No comma is used in writing 999 or smaller numbers. One comma is used in writing each of the numbers from 1000 through 1010.
Thus, 11 commas are used in total.

Sample Input 2

27182818284590

Sample Output 2

107730272137364

见题面 Input 部分

见题面 Output 部分