n = int(input())
if n % 2 == 0:
    print(1 / 2)
elif n == 1:
    print(1)
else:
    print(((n + 1) / 2) / n) n = int(input()) n int(input()) int input() input if n % 2 == 0:
    print(1 / 2)
elif n == 1:
    print(1)
else:
    print(((n + 1) / 2) / n) n % 2 == 0 n % 2 n 2 0 print(1 / 2) print 1 / 2 1 2 elif n == 1:
    print(1) n == 1 n 1 print(1) print 1 print(((n + 1) / 2) / n) print ((n + 1) / 2) / n (n + 1) / 2 n + 1 n 1 2 n n = int(input()) int(input()) n
n = int(input())
if n % 2 == 0:
    print(1 / 2)
elif n == 1:
    print(1)
else:
    print(((n + 1) / 2) / n)