N = int(input())


if N == 1:
    print(1.0)
elif N % 2 == 0:
    print(0.5)
    exit()
elif N % 2 != 0:
    print((N - (N // 2)) / N) N = int(input()) N int(input()) int input() input if N == 1:
    print(1.0)
elif N % 2 == 0:
    print(0.5)
    exit()
elif N % 2 != 0:
    print((N - (N // 2)) / N) N == 1 N 1 print(1.0) print 1.0 elif N % 2 == 0:
    print(0.5)
    exit() N % 2 == 0 N % 2 N 2 0 print(0.5) print 0.5 exit() exit elif N % 2 != 0:
    print((N - (N // 2)) / N) N % 2 != 0 N % 2 N 2 0 print((N - (N // 2)) / N) print (N - (N // 2)) / N N - (N // 2) N N // 2 N 2 N N = int(input()) int(input()) N
N = int(input())


if N == 1:
    print(1.0)
elif N % 2 == 0:
    print(0.5)
    exit()
elif N % 2 != 0:
    print((N - (N // 2)) / N)