Problem Description

There is an analog clock showing $ n $ hours and $ m $ minutes. Calculate the smaller angle between the hour hand and the minute hand in degrees.

Input Format

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

$ n $ $ m $

• The first line contains two integers $n,\ m\ (\ 0\ ≦\ n\ ≦\ 23,\ 0\ ≦\ m\ ≦\ 59\ )$ separated by a space, representing the time on the analog clock.

Output Format

Output the angle between the hour hand and the minute hand on the first line. The absolute or relative error should be within $ 10^{-4} $.

Do not forget the newline at the end.

Sample Input and Output

Sample Input #1

15 0

Sample Output #1

90

Sample Input #2

3 17

Sample Output #2

3.5

Sample Input #3

0 0

Sample Output #3

0

Sample Input #4

6 0

Sample Output #4

180

Sample Input #5

23 59

Sample Output #5

5.5000

Notes/Hints

Sample Explanation 1

The hour hand and minute hand of the clock are as shown in the following diagram: The red arrow is the minute hand, and the orange arrow is the hour hand.

Sample Explanation 2

The hour hand and minute hand of the clock are as shown in the following diagram:

见题面 Input 部分

见题面 Output 部分