## Problem Description

The troop is advancing. The length of the queue is x meter. The commander is at the front of the queue, riding his horse. The crier is at the end of the queue. If something happen, the crier should talk to the commander. Now, the crier run to the commander. Then run back. We know the troop has advanced x meter. So what is the number of meter the crier run. You can assume the speed of the crier is bigger than the troop.

## Input

There are multiple test case, in every case, there will be a real number x. which means the distance the troop advances. 0 < x < 10^1000

## Output

For each test case you should print the answer. Use the print format as below. Print a blank line after each case. Because of the Accuracy error,
If answer >= 100000,you should just output the front five digit. Else round to the four digits after the decimal point.

## Sample Input

100
100000

## Sample Output

Case 1
241.4214
Case 2
24142

## Source

FOJ有奖月赛-2009年11月