Sphere#1853
Place points on the surface of a sphere so that the minimum pairwise distance among these points is as large as possible.
The input contains integers (1 \leq R \leq 1000) and (2 \leq N \leq 4) — the radius of the sphere and the number of points, respectively.
Output a single real number: the largest possible value of the minimum pairwise distance between these points.
Print the first characters of the answer (including the decimal separator), without rounding.
Example 1