Problem Description

Takahashi ran 50 meters in $ s $ seconds.

Output the average speed in meters per second that Takahashi ran.

Input Format

The input is given from the standard input in the following format:

$ s $

• The first line contains an integer $s\ (1≦s≦20)$ representing the number of seconds Takahashi took to run 50 meters.

Output Format

Output the average speed in meters per second that Takahashi ran in one line. Make sure to include a newline at the end of the output.

The output will be accepted if the absolute or relative error is within $ 10^{-3} $.

Sample Input and Output

Sample Input #1

10

Sample Output #1

5

Sample Input #2

7

Sample Output #2

7.142857142857

Notes/Hints

Sample Explanation 1

If Takahashi runs at a speed of 5 meters per second, he can run 50 meters in 10 seconds.

Sample Explanation 2

Note that the output may be a decimal.

见题面 Input 部分

见题面 Output 部分