n = int(input())

if n >= 2:
    print((1-(n//2 / n)))
else:
    print(n / n) n = int(input()) n int(input()) int input() input if n >= 2:
    print((1-(n//2 / n)))
else:
    print(n / n) n >= 2 n 2 print((1-(n//2 / n))) print 1-(n//2 / n) 1 n//2 / n n//2 n 2 n print(n / n) print n / n n n n = int(input()) int(input()) n
n = int(input())

if n >= 2:
    print((1-(n//2 / n)))
else:
    print(n / n)