import sys

readline = sys.stdin.readline
MOD = 10 ** 9 + 7
INF = float('INF')
sys.setrecursionlimit(10 ** 5)


def main():
    N = int(readline())

    odd = 0
    for i in range(1, N + 1):
        if i % 2 == 1:
            odd += 1

    print(odd / N)


if __name__ == '__main__':
    main() import sys sys readline = sys.stdin.readline readline sys.stdin.readline sys.stdin sys stdin readline MOD = 10 ** 9 + 7 MOD 10 ** 9 + 7 10 ** 9 10 9 7 INF = float('INF') INF float('INF') float 'INF' sys.setrecursionlimit(10 ** 5) sys.setrecursionlimit sys setrecursionlimit 10 ** 5 10 5 def main():
    N = int(readline())

    odd = 0
    for i in range(1, N + 1):
        if i % 2 == 1:
            odd += 1

    print(odd / N) main N = int(readline()) N int(readline()) int readline() readline odd = 0 odd 0 for i in range(1, N + 1):
        if i % 2 == 1:
            odd += 1

     i range(1, N + 1) range 1 N + 1 N 1 if i % 2 == 1:
            odd += 1

     i % 2 == 1 i % 2 i 2 1 odd += 1 odd 1 print(odd / N) print odd / N odd N if __name__ == '__main__':
    main() __name__ == '__main__' __name__ '__main__' main() main INF = float('INF') float('INF') INF def main():
    N = int(readline())

    odd = 0
    for i in range(1, N + 1):
        if i % 2 == 1:
            odd += 1

    print(odd / N) def main():
    N = int(readline())

    odd = 0
    for i in range(1, N + 1):
        if i % 2 == 1:
            odd += 1

    print(odd / N) main readline = sys.stdin.readline sys.stdin.readline readline MOD = 10 ** 9 + 7 10 ** 9 + 7 MOD
import sys

readline = sys.stdin.readline
MOD = 10 ** 9 + 7
INF = float('INF')
sys.setrecursionlimit(10 ** 5)


def main():
    N = int(readline())

    odd = 0
    for i in range(1, N + 1):
        if i % 2 == 1:
            odd += 1

    print(odd / N)


if __name__ == '__main__':
    main()
