Cutting Colored Paper

Time limit0.5sMemory limit1024 MB

Summary

Given the area W of one half of a square sheet cut along its width, print the perimeter of the original square.

Level: Easy2 of 10
Topics: Math, Implementation
Solved: No attempts yet

Problem

Galrae bought a square sheet of colored paper this time, but it is too large for his taste, so he decides to cut it in half.

Given the area $W$ of one half after the paper is cut exactly in half along its width, find the perimeter of the original sheet. The side length of the original sheet is even.

Input

The first line contains an integer $W$ . ( $2 \le W \le 20\,000$ , $W$ is even)

Only inputs where an answer exists are given.

Output

Print the perimeter of the original sheet.

Examples1

Example 1
Input
```
18
```
Expected output
```
24
```