# radius.py

import math

print("    n   r(n)")
for n in [10, 100, 1000, 10000, 20000, 30000, 50000, 60000]:
  r = 1
  for i in range(3, n+1):
    r = r/math.cos(math.pi/i)
  print(f"{n:5d}  {r:.4f}")