import math
N = int(input())

if N%2 == 0:
    print(1/2)
else:
    print(math.ceil(N/2)/N) import math math N = int(input()) N int(input()) int input() input if N%2 == 0:
    print(1/2)
else:
    print(math.ceil(N/2)/N) N%2 == 0 N%2 N 2 0 print(1/2) print 1/2 1 2 print(math.ceil(N/2)/N) print math.ceil(N/2)/N math.ceil(N/2) math.ceil math ceil N/2 N 2 N N = int(input()) int(input()) N
import math
N = int(input())

if N%2 == 0:
    print(1/2)
else:
    print(math.ceil(N/2)/N)