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 Java8 (OpenJDK 1.8.0) (judge verdict: Runtime Error)

import java.util.*;

public class Main{
	public static void main (String[] args){
		Scanner sc = new Scanner(System.in);
		int counter=1;
		int N= sc.nextInt();
		while (N<1||N>100)
			N=sc.nextInt();
		int a= sc.nextInt();
		while(a>N)
			a=sc.nextInt();
		if (N%2==0){
			for (int i=2; i<=N;i+=2)
				counter++;
		}
		else{
			for(int i=1; i<=N; i+=2)
			 	counter++;
		}
		System.out.println(counter/N);
	}
}