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