n = int(input())

b = range(1, n)

a = b[::2]
print(1 - (len(a) / n)) n = int(input()) n int(input()) int input() input b = range(1, n) b range(1, n) range 1 n a = b[::2] a b[::2] b ::2 2 print(1 - (len(a) / n)) print 1 - (len(a) / n) 1 len(a) / n len(a) len a n b = range(1, n) range(1, n) b n = int(input()) int(input()) n a = b[::2] b[::2] a
n = int(input())

b = range(1, n)

a = b[::2]
print(1 - (len(a) / n))
