Score : $100$ points
Given is an integer $N$.
Takahashi chooses an integer $a$ from the positive integers not greater than $N$ with equal probability.
Find the probability that $a$ is odd.
Input is given from Standard Input in the following format:
$N$
Print the probability that $a$ is odd. Your output will be considered correct when its absolute or relative error from the judge's output is at most $10^{-6}$.
4
0.5000000000
There are four positive integers not greater than $4$: $1$, $2$, $3$, and $4$. Among them, we have two odd numbers: $1$ and $3$. Thus, the answer is $\frac{2}{4} = 0.5$.
5
0.6000000000
1
1.0000000000