a = int(input())

if a % 2 == 1: print( ((a-1)/2 + 1)/a )
else: print(0.5) a = int(input()) a int(input()) int input() input if a % 2 == 1: print( ((a-1)/2 + 1)/a )
else: print(0.5) a % 2 == 1 a % 2 a 2 1 a = int(input()) int(input()) a
a = int(input())

if a % 2 == 1: print( ((a-1)/2 + 1)/a )
else: print(0.5)
