Problem J

Find the Latitude

Time Limit

1 Second

 

We are dealing with a very well known problem here. A man lives in a hut. On one fine morning he wakes up goes n km to the north, and then he goes n km to the east and then he goes n km to the south to reach his hut again. Your job is to determine the latitude of his hut. You can assume that the man lives on a planet which is a perfect sphere and the man can walk at any location of his planet (no seas, no mountains, no check points, only plain land). If there is more than one solution you just need to find the first 10 smaller solutions. One obvious solution is the south pole. We don't need that.

 

Input

The input file contains several lines of inputs. Each line contains two integers R (0<R<100000) and n (R/100<=n<=R/8). Here R is the radius of earth in km and n is the distance covered in km in each journey as described in the problem statement. Input is terminated by a line where R=0 and n=0.

 

Output

For each line of input first produce the serial of the output as shown in the sample output. Then produce at most 10 lines, which contain the latitude of the man’s house in degree. The degree values should have five digits after the decimal point.

 

 

Sample Input

Output for Sample Input

1000 10

1000 20

0 0

Case 1:

89.33585

89.38145

89.39665

89.40424

89.40880

89.41184

89.41402

89.41564

89.41691

89.41792

Case 2:

88.67171

88.76290

88.79329

88.80849

88.81761

88.82369

88.82803

88.83129

88.83382

88.83585

 

Problemsetter: Shahriar Manzoor

Member of Elite Problemsetters' Panel

 

Hint:

Consider a parallel on the northern Hemisphere that has a circumference of n mile (Parallel A in the figure below). We can select an arbitrary point on this parallel, move one mile south to another parallel (parallel B in figure below). This is a possible position of the man’s tent. I mean the man’s tent can be anywhere on this parallel. Other such parallel can be found using similar approach.