def main():
    n = int(input())
    # 奇数の数
    m = n - (n // 2)
    ans = m / n
    print(ans)
    
if __name__ == '__main__':
    main() def main():
    n = int(input())
    # 奇数の数
    m = n - (n // 2)
    ans = m / n
    print(ans)
     main n = int(input()) n int(input()) int input() input m = n - (n // 2) m n - (n // 2) n n // 2 n 2 ans = m / n ans m / n m n print(ans) print ans if __name__ == '__main__':
    main() __name__ == '__main__' __name__ '__main__' main() main def main():
    n = int(input())
    # 奇数の数
    m = n - (n // 2)
    ans = m / n
    print(ans)
     def main():
    n = int(input())
    # 奇数の数
    m = n - (n // 2)
    ans = m / n
    print(ans)
     main
def main():
    n = int(input())
    # 奇数の数
    m = n - (n // 2)
    ans = m / n
    print(ans)
    
if __name__ == '__main__':
    main()