import sys


# input = sys.stdin.readline

def main():
    N = int(input())
    eve = int(N//2)
    print((N-eve)/N)


if __name__ == "__main__":
    main() import sys sys def main():
    N = int(input())
    eve = int(N//2)
    print((N-eve)/N) main N = int(input()) N int(input()) int input() input eve = int(N//2) eve int(N//2) int N//2 N 2 print((N-eve)/N) print (N-eve)/N N-eve N eve N if __name__ == "__main__":
    main() __name__ == "__main__" __name__ "__main__" main() main def main():
    N = int(input())
    eve = int(N//2)
    print((N-eve)/N) def main():
    N = int(input())
    eve = int(N//2)
    print((N-eve)/N) main
import sys


# input = sys.stdin.readline

def main():
    N = int(input())
    eve = int(N//2)
    print((N-eve)/N)


if __name__ == "__main__":
    main()