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 i,count=1;
  float n,a;
    scanf("%f",&n);
    if(n==1)
    {
      printf("1");
    }
  else
  {
    for(i=2;i<=n;i++)
      { 
      if(i%2==1)
        { 
        count++;
        }
      }
     a=count/n;
     printf("%.10f",a);
  }
 
  return 0;
  }