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 Java7 (OpenJDK 1.7.0) (judge verdict: Accepted)

import java.util.Scanner;

public class Main {
	static int intN =0;
	static int sosuCnt =0;

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String n = sc.nextLine();
		//String[] h = sc.nextLine().split(" ");

		int intN = Integer.parseInt(n);

		double sum=0;
		
		if (intN==1) {
			sum=1.0000000000;
		} else if(intN%2==0) {
			sum=0.5000000000;
		} else {
			sum=1-(double)(intN/2)/intN;
		}

		System.out.println(sum);


		//int a = Integer.parseInt("");
		//for (int i = 0;i < intN;i++) {
		//sum=sum+i;
	//}

	}
}