def some():
    n = int(input())
    odds = len([i for i in range(1, n+1) if i%2 != 0])
    print(odds/n)
some() def some():
    n = int(input())
    odds = len([i for i in range(1, n+1) if i%2 != 0])
    print(odds/n) some n = int(input()) n int(input()) int input() input i for i in range(1, n+1) if i%2 != 0 for i in range(1, n+1) if i%2 != 0 i range(1, n+1) range 1 n+1 n 1 i%2 != 0 i%2 i 2 0 if i%2 != 0 i odds = len([i for i in range(1, n+1) if i%2 != 0]) odds len([i for i in range(1, n+1) if i%2 != 0]) len [i for i in range(1, n+1) if i%2 != 0] print(odds/n) print odds/n odds n some() some def some():
    n = int(input())
    odds = len([i for i in range(1, n+1) if i%2 != 0])
    print(odds/n) def some():
    n = int(input())
    odds = len([i for i in range(1, n+1) if i%2 != 0])
    print(odds/n) some
def some():
    n = int(input())
    odds = len([i for i in range(1, n+1) if i%2 != 0])
    print(odds/n)
some()