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# (.NET Core 3.1.201) (judge verdict: Wrong Answer)

using System;
using System.Collections.Generic;
using System.Dynamic;
using System.Linq;
using System.Security.Cryptography.X509Certificates;

namespace atcorder
{
    class Program
    {
        static void Main(string[] args)
        {
            double N = double.Parse(Console.ReadLine());
            if(N % 2 == 0)
            {
                Console.WriteLine(N / 2 / N);
            }
            else
            {
                Console.WriteLine((N / 2 + 1) / N);
            }

        }
    }
}

//文字配列の取得
//string[] strArray = Console.ReadLine().Split(' ').ToArray();
//string S = strArray[0];
//string T = strArray[1];

//文字列の取得
//string s = Console.ReadLine();

//数字配列の取得
//int[] intArray = Console.ReadLine().Split(' ').Select(i => int.Parse(i)).ToArray();
//int H = intArray[0];
//int W = intArray[1];

//数字の取得
//int N = int.Parse(Console.ReadLine());

//リスト型(int)の取得
//List<int> A = new List<int>(Console.ReadLine().Split(' ').Select(i => int.Parse(i)).ToArray());

//出力
//Console.WriteLine(ans);
//Console.WriteLine("Yes");
//Console.WriteLine("No");
//Console.WriteLine(cnt);