N = int(input())
if N%2 == 0:
  print(0.5000000000)
else:
  odd = N//2 + 1
  print(odd/N) N = int(input()) N int(input()) int input() input if N%2 == 0:
  print(0.5000000000)
else:
  odd = N//2 + 1
  print(odd/N) N%2 == 0 N%2 N 2 0 print(0.5000000000) print 0.5000000000 odd = N//2 + 1 odd N//2 + 1 N//2 N 2 1 print(odd/N) print odd/N odd N odd = N//2 + 1 N//2 + 1 odd N = int(input()) int(input()) N
N = int(input())
if N%2 == 0:
  print(0.5000000000)
else:
  odd = N//2 + 1
  print(odd/N)