Problem Description

Chuanzhi Specialized Training College's evaluation system for the Java Programming course is as follows:

First, all students will have a written score, which is guaranteed to be an integer between $[0, 100]$.

If the written score is 90 or above, then their GPA (Weighted Average Grade) is the full score of 4.0.

If the written score is between 60 and 89, then for every point less than 90, their GPA will decrease by 0.1 from 4.0.

If the written score is below 60, the kind teacher will give them special consideration. Specifically, if their score is $x$, the teacher will adjust their score to $\sqrt{x} \times 10$ (rounded down) and then calculate their GPA.

If after adjustment the student's score still does not reach 60, then they have failed, and their GPA is 0.

Now, given a student's final written score, please output their final GPA.

Input Format

A single line containing an integer $x$, representing the student's final written score.

Output Format

A floating-point number with one decimal place, representing the student's GPA.

Please note that if there is a trailing .0, it should be retained.

Sample Input and Output

Sample Input #1

99

Sample Output #1

4.0

Sample Input #2

88

Sample Output #2

3.8

Sample Input #3

12

Sample Output #3

0.0

Notes

For 20% of the data, it satisfies $90 \leq x \leq 100$;
For an additional 30% of the data, it satisfies $60 \leq x \leq 100$;
For 100% of the data, it satisfies $0 \leq x \leq 100$.

见题面 Input 部分

见题面 Output 部分