101952: [AtCoder]ABC195 C - Comma

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?

Constraints

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

Input

Input is given from Standard Input in the following format:

$N$

Output

Print the total number of commas.

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