Contest Duration: - (local time) (100 minutes) Back to Home
C - Comma /

Time Limit: 2 sec / Memory Limit: 1024 MB

### 制約

• 1 \leq N \leq 10^{15}
• N は整数

N

### 出力

コンマが書かれる回数の合計を出力せよ。

1010

### 出力例 1

11

999 以下の数を書くときにはコンマは書かれません。1000 以上 1010 以下の数を書くときには、それぞれ 1 回ずつコンマが書かれます。

よって、コンマは全部で 11 回書かれます。

27182818284590

### 出力例 2

107730272137364

Score : 300 points

### 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.

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.

27182818284590

107730272137364