Problem:
Score : 100 points

Problem Statement

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.

Constraints

1 \leq N \leq 100

Input

Input is given from Standard Input in the following format:

N

Output

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}.

Sample Input 1

4

Sample Output 1

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.

Sample Input 2

5

Sample Output 2

0.6000000000

Sample Input 3

1

Sample Output 3

1.0000000000

Solution in C (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>
int main()
{
  int n,c,d,p;
  float e,f,g,h;
  scanf("%d",&n);
  if(n==1)
  {
    printf("1.0000000000");
  }
  else if(n%2==0)
  {
  	c =n/2;
  	e = c;
  	f = e/n;
  	printf("%f",f);
  }
  else if(n%2!=0)
  {
  	d = n-1;
  	d = d/2;
  	d = d+1;
  	g = d;
  	h = g/n;
  	printf("%f",h);
  }
}