N=int(input())
print(len(range(1,N+1,2))/N) N=int(input()) N int(input()) int input() input print(len(range(1,N+1,2))/N) print len(range(1,N+1,2))/N len(range(1,N+1,2)) len range(1,N+1,2) range 1 N+1 N 1 2 N N=int(input()) int(input()) N
N=int(input())
print(len(range(1,N+1,2))/N)