N = int(input())
print("0.5" if N % 2 == 0 else ((N//2)+1)/N )  N = int(input()) N int(input()) int input() input print("0.5" if N % 2 == 0 else ((N//2)+1)/N ) print "0.5" if N % 2 == 0 else ((N//2)+1)/N N % 2 == 0 N % 2 N 2 0 "0.5" ((N//2)+1)/N (N//2)+1 N//2 N 2 1 N N = int(input()) int(input()) N
N = int(input())
print("0.5" if N % 2 == 0 else ((N//2)+1)/N ) 