num = int(input())

if num%2 == 0:
  ans = float(1/2)
  
else:
  ans = float((num//2 + 1)/num)

print(ans) num = int(input()) num int(input()) int input() input if num%2 == 0:
  ans = float(1/2)
  
else:
  ans = float((num//2 + 1)/num) num%2 == 0 num%2 num 2 0 ans = float(1/2) ans float(1/2) float 1/2 1 2 ans = float((num//2 + 1)/num) ans float((num//2 + 1)/num) float (num//2 + 1)/num num//2 + 1 num//2 num 2 1 num print(ans) print ans ans = float(1/2) float(1/2) ans num = int(input()) int(input()) num ans = float((num//2 + 1)/num) float((num//2 + 1)/num) ans
num = int(input())

if num%2 == 0:
  ans = float(1/2)
  
else:
  ans = float((num//2 + 1)/num)

print(ans)