import math
A = int(input())
print(math.ceil(A / 2) / A)  import math math A = int(input()) A int(input()) int input() input print(math.ceil(A / 2) / A) print math.ceil(A / 2) / A math.ceil(A / 2) math.ceil math ceil A / 2 A 2 A A = int(input()) int(input()) A
import math
A = int(input())
print(math.ceil(A / 2) / A) 