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: Accepted)

import java.io.PrintWriter;
import java.util.Scanner;

public class Main {
    static private Scanner scan = new Scanner(System.in);
    public static void main(String args[]) {
//        int int1 = Integer.parseInt(scan.next());
//        int int2 = Integer.parseInt(scan.next());
//        int int3 = Integer.parseInt(scan.next());
//        int int4 = Integer.parseInt(scan.next());
        double db = Double.parseDouble(scan.next());
        int ans_int = 0;
        String ans = "";
//        String temp_str1 = "";
//        String temp_str2 = "";
        int temp_int1 = 0;
//        String str1 = scan.next();
//        String str2 = scan.next();
//        String str3 = scan.next();

        double ans_dob = 0;
        if(db % 2 == 0){
            ans_dob= (db/2)/db;
        }else{
            ans_dob = (db/2+0.5)/db;
        }

        PrintWriter out = new PrintWriter(System.out);
        out.println(ans_dob);
        out.flush();
        scan.close();
    }
}